How to clear stack back to root activity when user leaves application?

Question

I have an application with 2 activities, LogonAct and MainAct. LogonAct is a logon activity which I want to force the user to go through each time they return to the application

Answer 1

You can do following:
1. set clearTaskOnLaunch = "true" in AndroidManifest, in declaration of main activity
2. in activity that must close:

@Override
public void onBackPressed(){
    moveTaskToBack(true);
}

so if user presses back - it comes back to homescreen if user launches aplication again - task stack clears and he comes to root main activity