One of the side effects of using free apps in the mobile world are ads. They help support the development of the app and allow the apps to be used by a wider base of people. Some developers, however, implement ads in shady and annoying ways in their apps to garner maximum views and clicks. This includes sub-par apps showing ads on the lock screen even if their functionality has nothing to do with it.
These ads end up confusing unsuspecting users and lead to a sub-par experience. Thankfully, Google is now heavily coming down on such apps and is banning such behaviour. The update policy mentions that unless an apps exclusive purpose serves that of a lock screen, they may not display ads or features on the lock screen of a device.
Unless the exclusive purpose of the app is that of a lockscreen, apps may not introduce ads or features that monetize the locked display of a device.
This means that apps like ES File Explorer, various apps from Go, VPNs etc. can no longer display ads on the lock screen since they don’t include a lockscreen functionality.
Considering apps with such shady tactics have existed on the Play Store for such a long time, its good to see Google finally stepping up and taking actions against them. Now let’s hope the company takes some kind of action to ensure that apps actually comply with these rules.[Via Developer Policy Center, Reddit]