• Missing this app

    From Qihe@Q@invalid.invalid to comp.mobile.android on Sat Jan 3 08:04:24 2026
    From Newsgroup: comp.mobile.android

    https://usb-scanner.soft112.com/

    It's not available (at least on google play store).
    And it seems there is no alternative android app for usb-otg
    scanners, is it?
    --
    Qihe
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From VanguardLH@V@nguard.LH to comp.mobile.android on Sat Jan 3 11:46:17 2026
    From Newsgroup: comp.mobile.android

    Qihe <Q@invalid.invalid> wrote:

    https://usb-scanner.soft112.com/

    It's not available (at least on google play store).
    And it seems there is no alternative android app for usb-otg
    scanners, is it?

    On an Android device, the Play Store will not show apps that are
    incompatible with your device. It does the compatibility check to
    determine what it shows you.

    Could be the app no longer exists at the Play Store. The author removed
    it, didn't meet Google's criteria, discovered to be untoward, and so on.

    At play.google.com, I searched on "Soft112", the web site you mention,
    but didn't find apps from that author. I noticed at the web site that
    the dev is called Accusoft, but a search on that at the Play Store still
    did not find a USB scanner from them. Perhaps Soft112 is a software distributor, not the program author. The web site quotes a price of
    $9.99, but now $0.99. Did you pay for this? The free trial only gives
    you 10 scans.

    Accusoft site doesn't mention they have a USB scanner app, but https://help.accusoft.com/USBScanner/v1.0/Help/index.html mentions an
    SDK. Who knows what you're getting at Soft112, or who wrote it.

    When I visit the Soft112 site, and click through the download links,
    eventually it reports "This app was removed from Google Play". They
    don't say why.

    Barcode Scanner App https://www.camcode.com/blog/top-barcode-scanner-apps/#android-only-apps
    "Built with Barcode Xpress for Mobile, AccusoftrCOs barcode SDK"

    Barcode Xpress is another SDK from Accusoft.

    I can find alternatives in an online search, but I haven't used any.
    You could go to the scanner maker's web site to see if they have an app
    for wireless scanning. For example, with an HP scanner/printer:

    https://www.hp.com/us-en/hp-app/overview.html

    For OTG wired printing with an HP printer, see (you have to ensure your
    printer support OTG communication):

    https://support.hp.com/us-en/document/ish_8030134-8030178-16

    You didn't mention the scanner make and model, so no one can check what features are supported by your scanner.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Maria Sophia@mariasophia@comprehension.com to comp.mobile.android on Sat Jan 3 13:01:18 2026
    From Newsgroup: comp.mobile.android

    Qihe wrote:
    https://usb-scanner.soft112.com/

    It's not available (at least on google play store).
    And it seems there is no alternative android app for usb-otg
    scanners, is it?

    Hi Qihe

    Happy New Year!

    I know less than nothing about on-the-go use models, but I looked it up for
    you so everything I say below isn't from me, per se, but from the results.

    My search tentatively confirms your observation though, that the specific
    "USB Scanner" app from Soft112 is not available on Google Play anymore.

    Apparently, there is no true Android app that can turn a USB-OTG handheld scanner (like a USB barcode scanner or USB flatbed scanner) into a plug-and-play scanning device.

    The apps that do exist only seem to handle USB storage, not USB imaging/scanning hardware such as this ad-supported example.
    <https://play.google.com/store/apps/details?id=com.otgbrow.files>
    (It's just an example - I'd look for FOSS scanners if I had time.)

    I looked up what USB-OTG scanners need in order to work on Android.
    It seems USB scanners (such as barcode guns, flatbed scanners, document scanners, etc.) expect three things to be available from a desktop:
    a. A full USB driver
    b. A TWAIN/WIA interface
    c. A desktop-class scanning API

    Apparently, Android does not support these protocols natively, so we might wonder if the Soft112 USB Scanner listing wasn't misleading in the 1st
    place as I can find nothing in a quick search that does the claimed tasks.

    Android can use USB barcode scanners (HID mode) because they act like a keyboard, and Android can use Wi-Fi & Bluetooth scanners because they
    generally have their own Android apps, and some apps, like Adobe Scan, & Microsoft Lens use the phone camera, but not the USB hardware.

    I could be wrong as I ran only a quick search, but from that one search results, I could find no Android app that supports USB-OTG document
    scanners or flatbed scanners. Instead I found only USB storage and HID
    barcode scanners.

    I can run a more detailed search later as I have to run right now.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Qihe@Q@invalid.invalid to comp.mobile.android on Sat Jan 3 23:22:04 2026
    From Newsgroup: comp.mobile.android

    VanguardLH <V@nguard.LH> ha scritto:

    https://usb-scanner.soft112.com/
    [...]
    The web site quotes a price of
    $9.99, but now $0.99. Did you pay for this? The free trial only gives
    you 10 scans.

    No, I didn't. Luky me ...I would have paid $10 for nothing. ;-)








    You could go to the scanner maker's web site to see if they have an app
    for wireless scanning. For example, with an HP scanner/printer:

    https://www.hp.com/us-en/hp-app/overview.html

    Yes, lot of modern machines work wireless, not the older USB
    scanners though. That's why it would have been nice having an app
    similar to "nokoprint".

    https://play.google.com/store/apps/details?id=com.nokoprint



    .
    For OTG wired printing with an HP printer, see (you have to ensure your printer support OTG communication):

    https://support.hp.com/us-en/document/ish_8030134-8030178-16

    Thank you. Maybe the otg communication solves these kind of issues
    (sometimes printers want to call home before printing). https://h30434.www3.hp.com/t5/Printer-Setup-Software-Drivers/How-do-I-use-this-printer-without-internet-service/td-p/8697900

    .
    You didn't mention the scanner make and model, so no one can check what features are supported by your scanner.

    CanoScan LiDE ... it doesn't support any wireless connection.
    --
    Qihe
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From VanguardLH@V@nguard.LH to comp.mobile.android on Sat Jan 3 18:40:43 2026
    From Newsgroup: comp.mobile.android

    Qihe <Q@invalid.invalid> wrote:

    VanguardLH <V@nguard.LH> ha scritto:

    https://usb-scanner.soft112.com/

    [...]
    The web site quotes a price of
    $9.99, but now $0.99. Did you pay for this? The free trial only gives
    you 10 scans.

    No, I didn't. Luky me ...I would have paid $10 for nothing. ;-)



    You could go to the scanner maker's web site to see if they have an app
    for wireless scanning. For example, with an HP scanner/printer:

    https://www.hp.com/us-en/hp-app/overview.html

    Yes, lot of modern machines work wireless, not the older USB
    scanners though. That's why it would have been nice having an app
    similar to "nokoprint".

    https://play.google.com/store/apps/details?id=com.nokoprint

    .
    For OTG wired printing with an HP printer, see (you have to ensure your
    printer support OTG communication):

    https://support.hp.com/us-en/document/ish_8030134-8030178-16

    Thank you. Maybe the otg communication solves these kind of issues
    (sometimes printers want to call home before printing). https://h30434.www3.hp.com/t5/Printer-Setup-Software-Drivers/How-do-I-use-this-printer-without-internet-service/td-p/8697900

    .
    You didn't mention the scanner make and model, so no one can check what
    features are supported by your scanner.

    CanoScan LiDE ... it doesn't support any wireless connection.

    Canon has several LiDE models. This one:

    https://www.usa.canon.com/shop/p/canoscan-lide-400

    says it does wireless printing using their Canoscan PRINT app, but the
    400 specs don't mention wireless.

    https://en.canon-cna.com/printers/wireless-printers/

    Guess that's their list of their printers that support wireless
    printing. No LiDE models are listed. No surprising considering those
    are so skinny as to fit inside a desk top drawer, so not enough room for
    RF radios. The [larger] Canon PIXMA printers have wifi.

    Some of the Canon printers can be connected to a wifi network. You'd
    print from your phone to the wifi printer device. Wouldn't be surprise
    the LiDE models don't have wireless printing again considering how thin
    they are. They're oversized pocket scanners. I had one years ago, but
    it was USB attached to my desktop PC.

    You can't transfer whatever you're trying to scan on your phone, like
    take a screen pic, to share via OneDrive, Google Drive, other other
    means to get onto your PC to then print via USB to the attached LiDE
    scanner?

    You're trying to (or did) use a setup not supported by the printer
    maker. Looks like you have to resort to wifi printing *if* your printer
    has wifi; else, check if there is a USB port on the printer where you
    could copy a file from the phone onto a USB flash drive, and then plug
    the USB flash drive into the printer. Again, considering the tight
    space for LiDE printers, they probably don't have data USB ports for
    input. Doesn't look like the PIXMA TS6420a that I have has a USB port
    for input. The HP I had before did.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Maria Sophia@mariasophia@comprehension.com to comp.mobile.android on Sun Jan 4 00:47:59 2026
    From Newsgroup: comp.mobile.android

    VanguardLH wrote:
    On an Android device, the Play Store will not show apps that are
    incompatible with your device. It does the compatibility check to
    determine what it shows you.

    While VanguardLH is correct, there's a trick to get around that
    compatibility check which doesn't require root and which works well.

    In summary, you can use the open source Google Play Store client (Aurora)
    which allows you to spoof most phones and API levels & ARM architecture.

    You can even use the open source Windows Google Play Store client, which is especially useful for very old phones due to it's generic client spoofing.

    I wrote a separate PSA on how to spoof your Android so that the Google Play Store repository is tricked into showing you all the possible APKs
    available so as to not derail this thread which is about a specific app.

    Newsgroups: comp.mobile.android
    Subject: PSA: Getting apps from Google Play Store that do not show for your device
    Date: Sun, 4 Jan 2026 00:41:54 -0500
    Message-ID: <10jcuj2$1v0a$1@nnrp.usenet.blueworldhosting.com>
    --
    My posts aim to explore how the system actually works beneath the surface,
    in ways most users may never understand because it's a subtle hidden path.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Arno Welzel@usenet@arnowelzel.de to comp.mobile.android on Sun Jan 4 16:24:41 2026
    From Newsgroup: comp.mobile.android

    Qihe, 2026-01-03 08:04:

    https://usb-scanner.soft112.com/

    It's not available (at least on google play store).
    And it seems there is no alternative android app for usb-otg
    scanners, is it?

    I am not aware of any universal app to use document scanners via
    USB-OTG. The app you mentioned was provided by "Accusoft" which does not
    exist any longer:

    <https://www.accusoft.com>

    <https://apryse.com/blog/apryse-acquires-scanbot-and-accusoft>

    However, some manufacturers provide apps to use the scanner their device
    via Wifi, like this:

    <https://play.google.com/store/apps/details?id=com.brother.mfc.brprint>

    So depending on which device you use, you may be able to use a
    manufacturer specific app.
    --
    Arno Welzel
    https://arnowelzel.de
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Qihe@Q@invalid.invalid to comp.mobile.android on Sun Jan 4 17:02:23 2026
    From Newsgroup: comp.mobile.android

    Maria Sophia <mariasophia@comprehension.com> ha scritto:

    Apparently, there is no true Android app that can turn a USB-OTG handheld scanner (like a USB barcode scanner or USB flatbed scanner) into a plug-and-play scanning device.

    There are a couple of android apps doing that with USB printers:
    "noko print" one of them. https://play.google.com/store/apps/details?id=com.nokoprint

    .
    This is the second (again only for printers): https://play.google.com/store/apps/details?id=com.dynamixsoftware.printershare

    .


    Apparently, Android does not support these protocols natively, so we might wonder if the Soft112 USB Scanner listing wasn't misleading in the 1st
    place as I can find nothing in a quick search that does the claimed tasks.

    I am going to read this: https://help.accusoft.com/USBScanner/v1.0/Help/gettingstarted.html



    I can run a more detailed search later as I have to run right now.

    Take your time.
    Thank you anyway.
    --
    Qihe
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Qihe@Q@invalid.invalid to comp.mobile.android on Sun Jan 4 17:28:50 2026
    From Newsgroup: comp.mobile.android

    Arno Welzel <usenet@arnowelzel.de> ha scritto:

    However, some manufacturers provide apps to use the scanner their device
    via Wifi, [...]

    Sorry, I forgot to mention my old scanner is USB only. I don't
    really mind to plug it into a PC as usual, but it would have been
    nice doing that on android too.
    --
    Qihe
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From VanguardLH@V@nguard.LH to comp.mobile.android on Sun Jan 4 11:21:29 2026
    From Newsgroup: comp.mobile.android

    Arno Welzel <usenet@arnowelzel.de> wrote:

    Qihe, 2026-01-03 08:04:

    https://usb-scanner.soft112.com/

    It's not available (at least on google play store).
    And it seems there is no alternative android app for usb-otg
    scanners, is it?

    I am not aware of any universal app to use document scanners via
    USB-OTG. The app you mentioned was provided by "Accusoft" which does not exist any longer:

    <https://www.accusoft.com>

    <https://apryse.com/blog/apryse-acquires-scanbot-and-accusoft>

    However, some manufacturers provide apps to use the scanner their device
    via Wifi, like this:

    <https://play.google.com/store/apps/details?id=com.brother.mfc.brprint>

    So depending on which device you use, you may be able to use a
    manufacturer specific app.

    From what I read online, the "USB Scanner" using OTG was only intended
    as a demo app to show off their API library they want to sell to app developers. Putting it in the Play Store gave it a wider audience.
    Guess they (or apryse that acquired Accusoft) didn't want to bother
    supporting nor continuing a demo app that users glomed onto for use as
    an everyday app. Or Google decided the Play Store was not a proper
    place for demo apps.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From VanguardLH@V@nguard.LH to comp.mobile.android on Mon Jan 5 00:25:42 2026
    From Newsgroup: comp.mobile.android

    Maria Sophia <mariasophia@comprehension.com> wrote:

    VanguardLH wrote:

    On an Android device, the Play Store will not show apps that are
    incompatible with your device. It does the compatibility check to
    determine what it shows you.

    While VanguardLH is correct, there's a trick to get around that
    compatibility check which doesn't require root and which works well.

    In summary, you can use the open source Google Play Store client
    (Aurora) which allows you to spoof most phones and API levels & ARM architecture.

    Did you try that method to see if the app was still at the Play store?
    If the app was removed, circumventing compatibility checks won't make
    the app magically reappear.

    https://play.google.com/store/apps/details?id=com.accusoft.usbscanner

    reports "the requested URL was not found on this server". The app isn't sitting there waiting for a compatibility check to succeed.

    Maybe the OP could find the APK to sideload onto his phone.

    https://accusoft-barcode-scanner.en.softonic.com/android https://apkpure.com/accusoft-barcode-scanner/com.accusoft.barcodescanner.client

    It is a paid app, so I don't know if sideloading without some means to
    retrieve licensing would let the OP continue using the app. Without a
    license key, the APK might be a trial version, and the user is expected
    to purchase and enter a license key.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Arno Welzel@usenet@arnowelzel.de to comp.mobile.android on Mon Jan 5 14:07:58 2026
    From Newsgroup: comp.mobile.android

    Qihe, 2026-01-04 17:28:

    Arno Welzel <usenet@arnowelzel.de> ha scritto:


    However, some manufacturers provide apps to use the scanner their device
    via Wifi, [...]

    Sorry, I forgot to mention my old scanner is USB only. I don't
    really mind to plug it into a PC as usual, but it would have been
    nice doing that on android too.

    I doubt that any app exists for this. There is no "generic" USB scanner protocol - so maintaining an app like this would mean a lot of work and
    money to spend for it to support existing scanners on the market. Since
    only a very small number of people would ever like to connect their old
    USB scanner to an Android device, I don't think, that any company will
    offer such a thing now.

    However there are a number of "scanner" apps for Android which take a
    picture of a document using the camera of the phone and create a PDF
    based on that. For example:

    <https://play.google.com/store/apps/details?id=com.indymobileapp.document.scanner>

    <https://play.google.com/store/apps/details?id=com.camscanner.documentscanner.pdfscanner.textscanner.photos.scanner>
    --
    Arno Welzel
    https://arnowelzel.de
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Qihe@Q@invalid.invalid to comp.mobile.android on Mon Jan 5 17:29:04 2026
    From Newsgroup: comp.mobile.android

    Arno Welzel <usenet@arnowelzel.de> ha scritto:

    I doubt that any app exists for this
    .
    So do I. Maybe on 2012 (some old sources wrote about that accusoft
    app) but not nowadays anymore.

    |
    There is no "generic" USB scanner protocol - so maintaining an app like this would mean a lot of work and
    money to spend for it to support existing scanners on the market
    .
    On Linux there is "Sane" (xsane, simple scan...) that works fine
    with several scanners. So maybe it's not impossible to get it on
    android. I mean theoretically.

    |
    Since only a very small number of people would ever like to connect their old
    USB scanner to an Android device, I don't think, that any company will
    offer such a thing now.

    I am with you.

    |
    However there are a number of "scanner" apps for Android which take a
    picture of a document using the camera of the phone and create a PDF
    based on that. For example:

    Not exactly the same clear PDF than you can get with a real
    scanner though.

    |
    <https://play.google.com/store/apps/details?id=com.indymobileapp.document.scanner>

    <https://play.google.com/store/apps/details?id=com.camscanner.documentscanner.pdfscanner.textscanner.photos.scanner>


    Thanks, I'll give them a try.
    --
    Qihe
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Chris@ithinkiam@gmail.com to comp.mobile.android on Mon Jan 5 21:47:55 2026
    From Newsgroup: comp.mobile.android

    Qihe <Q@invalid.invalid> wrote:
    Arno Welzel <usenet@arnowelzel.de> ha scritto:

    I doubt that any app exists for this
    .
    So do I. Maybe on 2012 (some old sources wrote about that accusoft
    app) but not nowadays anymore.

    |
    There is no "generic" USB scanner protocol - so maintaining an app like
    this would mean a lot of work and
    money to spend for it to support existing scanners on the market
    .
    On Linux there is "Sane" (xsane, simple scan...) that works fine
    with several scanners. So maybe it's not impossible to get it on
    android. I mean theoretically.

    |
    Since only a very small number of people would ever like to connect their old
    USB scanner to an Android device, I don't think, that any company will
    offer such a thing now.

    I am with you.

    |
    However there are a number of "scanner" apps for Android which take a
    picture of a document using the camera of the phone and create a PDF
    based on that. For example:

    Not exactly the same clear PDF than you can get with a real
    scanner though.

    You can get surprisingly good results. For most purposes they are easily
    good enough. Depending on the quality of your phone's camera, obviously.

    <https://play.google.com/store/apps/details?id=com.indymobileapp.document.scanner>

    <https://play.google.com/store/apps/details?id=com.camscanner.documentscanner.pdfscanner.textscanner.photos.scanner>


    Thanks, I'll give them a try.





    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Arno Welzel@usenet@arnowelzel.de to comp.mobile.android on Tue Jan 6 00:09:41 2026
    From Newsgroup: comp.mobile.android

    Qihe, 2026-01-05 17:29:

    Arno Welzel <usenet@arnowelzel.de> ha scritto:

    I doubt that any app exists for this
    .
    So do I. Maybe on 2012 (some old sources wrote about that accusoft
    app) but not nowadays anymore.

    |
    There is no "generic" USB scanner protocol - so maintaining an app like this would mean a lot of work and
    money to spend for it to support existing scanners on the market
    .
    On Linux there is "Sane" (xsane, simple scan...) that works fine
    with several scanners. So maybe it's not impossible to get it on
    android. I mean theoretically.

    SANE (at least the scanner backend) is developed in C not Java or Kotlin:

    <https://gitlab.com/sane-project/backends/tree/master>

    So porting this to Android would require at least building packages for
    several device types. Yes, in theory this may be possible, but still a
    lot of work.
    --
    Arno Welzel
    https://arnowelzel.de
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From VanguardLH@V@nguard.LH to comp.mobile.android on Mon Jan 5 18:05:22 2026
    From Newsgroup: comp.mobile.android

    Qihe <Q@invalid.invalid> wrote:

    https://usb-scanner.soft112.com/

    It's not available (at least on google play store).
    And it seems there is no alternative android app for usb-otg
    scanners, is it?

    In a subthread spurred by Maria, I checked if there other places you
    could get the Accusoft USB Scanner app. Take a look at my reply to
    Maria (Message-ID: <tgzit5l9mmv9.dlg@v.nguard.lh>) for those sites where
    you could sideload the APK for that app.

    I've heard the uninstalling an app does not remove its APK. Maybe there
    is a way to rescusitate an app from a remnant APK still residing on your Android device.

    We don't know if you had the app, and uninstalled it, or are trying to
    install it on a new phone. Maybe you still have the app, but it stopped working with your scanner in which case it is unlikely there is a newer
    version of what was a demo app to Accusoft to show off their library.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Frank Slootweg@this@ddress.is.invalid to comp.mobile.android on Tue Jan 6 11:28:40 2026
    From Newsgroup: comp.mobile.android

    Chris <ithinkiam@gmail.com> wrote:
    Qihe <Q@invalid.invalid> wrote:
    Arno Welzel <usenet@arnowelzel.de> ha scritto:
    [...]
    However there are a number of "scanner" apps for Android which take a
    picture of a document using the camera of the phone and create a PDF
    based on that. For example:

    Not exactly the same clear PDF than you can get with a real
    scanner though.

    You can get surprisingly good results. For most purposes they are easily
    good enough. Depending on the quality of your phone's camera, obviously.

    Indeed. Recently, I saw an article from a professional photographer
    who recommended 'PhotoScan by Google Photos' for scanning photos.

    Because I didn't remember the name, I just now did a Google search on
    'google scan app for android' and Google's 'AI Overview' came up with 'PhotoScan by Google Photos' (which amongst others offers glare removal, auto-cropping and smart rotation), but also mentioned the scan function
    in the Google Drive app.

    Just now, I quickly tried the latter and I find it amazing! I put a
    brochure on the table, just pointed roughly at it and got a perfect
    scan! The scan contained only the brochure, not any part of the table
    and the brochure was perfectly upright. You can save in PDF or JPEG
    format. Of course the 'down side' is that the scans are saved to your
    Google Drive, but if you use that anyway, it's no issue and you can
    always download the Google Drive copy to some other place and then
    delete it.

    As you say, the quality of these scans depend on the quality/
    resolution of your camera and the resolution (dpi) of most scanners is
    much higher than the comparable resolution of a phone camera, but for
    many uses, the results from a phone scan will be more than adequate.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Andy Burns@usenet@andyburns.uk to comp.mobile.android on Tue Jan 6 13:23:58 2026
    From Newsgroup: comp.mobile.android

    Frank Slootweg wrote:

    Recently, I saw an article from a professional photographer
    who recommended 'PhotoScan by Google Photos' for scanning photos.

    Because I didn't remember the name, I just now did a Google search on 'google scan app for android' and Google's 'AI Overview' came up with 'PhotoScan by Google Photos' (which amongst others offers glare removal, auto-cropping and smart rotation), but also mentioned the scan function
    in the Google Drive app.

    The standard Pixel camera app detects when I'm taking an image of a
    "document" and automatically crops/de-skews, I can manually choose B&W
    or greyscale instead of colour, option to add multi-pages as single PDF document ...




    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Maria Sophia@mariasophia@comprehension.com to comp.mobile.android on Tue Jan 6 23:47:55 2026
    From Newsgroup: comp.mobile.android

    VanguardLH wrote:
    I've heard the uninstalling an app does not remove its APK. Maybe there
    is a way to rescusitate an app from a remnant APK still residing on your Android device.

    Hi Vanguard,

    Happy New Year!

    You bring up a good point that uninstalling an app doesn't do, in many
    cases, what we'd all intuitively would think uninstalling an app would do.

    Assuming we're not rooted...

    Uninstalling an app only removes the user-installed copy if the app was originally installed in the user partition. However, if the app was a
    system app then its APK lives in the system partition which is read only.
    adb shell pm uninstall --user 0 com.android.chrome

    In that case uninstalling it, whether through the normal UI or with adb for
    a specific user, only removes the user data and the user specific install record. The base APKs in the system partition stay in place.

    If the app was a user installed app then uninstalling it removes both the
    APK and its data because those live in the writeable data partition.

    The distinction here is that a system app is an app whose base APKs are
    stored in the system partition. Modern Android uses split APKs, so a system
    app may include a base APK and multiple split APKs for config or features.
    The system partition is read only on normal devices so these APKs cannot be removed without root. But the group of bundled APKs for any given app come
    and go together as a bundle when uninstalling the system or user app.

    A user app is an app whose APKs live in the data partition under /data/app. That partition is writeable so uninstalling a user app removes its APKs and
    its data.

    Many common apps, such as Chrome, are shipped as system apps on many
    devices. In that case Chrome's base APKs are stored in the system
    partition. When you uninstall Chrome with adb for user 0 you are not
    deleting those APKs. You are only removing the user specific install
    record and the user data. The base APKs remain in the system partition.

    If Chrome is a system app, and if the user uninstalls it with adb,
    Chrome appears to be gone because Android does not launch apps directly
    from the system partition. Android launches apps based on the user
    specific install record stored in the user partition.

    When we uninstall a system app for a specific user, Android removes:
    1. The user specific install record
    2. The user data directory
    3. The launcher icon and visibility for that user

    Once those are removed, Android treats the app as not installed for that
    user even though the base APKs still exist in the system partition.

    The system partition only stores the original APKs. It is not consulted to decide whether the app is installed. The user partition controls whether
    the app is visible, launchable, and considered installed.

    So the app looks gone because Android checks the user partition to decide
    what apps exist for that user. The system partition only holds the files,
    not the install state.

    However, some devices ship Chrome as a user app instead. In that case uninstalling it removes the APKs because they live in the data partition.

    So a system app does not live in both partitions. Its base APKs live only
    in the system partition. What lives in the user partition is the user
    specific data and the install record. Removing those makes the app appear
    gone even though the base APKs are still present.

    Notice this means you're correct that in some cases, removing the app from
    the user view if it's a system app but it can easily be reinstalled since
    the original APKs are still there (in the system partition).
    adb shell cmd package install-existing com.android.chrome

    This restores the app for user 0 using the base APKs that still exist in
    the system partition.

    Yes, I know, it's NOT intuitive.
    --
    Just one person paying it forward by helping others who later help me.
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