Some Android apps update without going through Google's Play Store, but those days are through. From now on, all apps will have to go through the store for their updates.
Android users will be aware that some of their apps, such as the Facebook app, can update without going through the official Play Store. By choosing to allow installations from unknown sources on their smartphones and tablets, an alert in an app could take users to updates hosted anywhere. Google has now seen it fit to change their content policy so that it bans developers from doing this. From now on, all updates must occur through Google Play.
According to the new policy:
"An app downloaded from Google Play may not modify, replace or update its own APK binary code using any method other than Google Play's update mechanism."
There is little in the means of getting around this rule, so from now on Facebook and anybody else using independent updates will have to fall in line. The rule doesn't however, seem to include apps which weren't originally acquired through Play.