How to resume Android Activity programmatically from background

Question

Situation:

1. Let\'s say I have currently working launched application Activity A.
2. After some time I am pressing \"Home\" button. Application A goes to b

Answer 1

Just establish a Service, doing whatever you want it to in the background. Or even better: Do something in the background, listen to it with a listener, bind a Service as soon as the event you waited for occurs (timer etc). Now that you are in the Service, you just call the Activity that should be on foreground like you would from anywhere else:

Intent i = new Intent(MyService.this, MyActivity.class);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
MyService.this.startActivity(i);