When you install an app the installation itself has a unique ID. When you login they can connect that unique ID with your personal credentials. This is quite common, because app developers want to know how many people use their apps and what version they use, and they want to send notifications for you to you and not somewhere else.
If the developers of the app follow this practice, which is pretty much default, they will know that you have uninstalled the app.
If it’s required to have the app installed and they discover that you don’t use it properly you may actually face problems the next time you try to extend your visa.
For example, if you check into a hotel, and the hotel sends the information that you have checked in (as they do), but they do not receive the same information from you and you are listed as uninstalled in the system... I wouldn’t recommend trying. This discrepancy would be automatically detected.
Instead, use a dedicated phone or tablet specifically for this purpose. It’s the safest option.