问题
I just want to understand how android apps update notification works. What are requirements for update notification to work (Google play store ,google services ??). Any useful link will be helpful.
I feel android has information of what are apps purchased by user, so when user connect to internet some service should look for updates available. If this assumption is correct then I want to know information about user owned apps is passed from device or kept server side ?? I wanted to know updates will work for a side loaded app or not.
回答1:
This is handled by the Play Store client. App history is associated with your Google account, that is why you can (automatically) install the same apps when you get a new device. It is kept on the server and cached on the device. Android keeps track of who installed a particular package (Play Store, side-load, etc.), but generally you can update an app as long as the updated is signed with the same certificate. Whether or not you will get notifications about side-loaded apps is entirely app to the Play Store app. Last I checked, it did show notifications, but you cannot rely on this. If you are dealing with side-loaded app, you'd better have your own update check mechanism.
来源：https://stackoverflow.com/questions/17465845/android-app-update-mechanism