Until now, most Android users never knew or noticed that it is somehow impossible receive updates for Android apps installed via 3rd party sources or peer-to-peer app sharing and or from unknown sources—directly from Google Play Store.
For security reasons, until now apps installed from third-party sources cannot be updated automatically over-the-air, as Google does not recognize them as Play Store apps and they do not show up in your Google account app list as well.
Late last year, Google announced plans to set up an automated mechanism to verify the genuineness of an app by adding a small amount of security metadata on top of each Android application package (in the APK Signing Block) distributed by its Play Store.
