I am trying to write an app that does something specific when it is brought back to the foreground after some amount of time. Is there a way to detect when an app is sent to the background or brought to the foreground?
The onPause() and onResume() methods are called when the application is brought to the background and into the foreground again. However, they are also called when the application is started for the first time and before it is killed. You can read more in Activity.
There isn't any direct approach to get the application status while in the background or foreground, but even I have faced this issue and found the solution with onWindowFocusChanged and onStop.
For more details check here Android: Solution to detect when an Android app goes to the background and come back to the foreground without getRunningTasks or getRunningAppProcesses.