How to close all the activities of my application?

You can achieve that by using BroadcastReceivers:

• Create a BaseActivity like this:

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public class BaseActivity extends Activity {
    private KillReceiver mKillReceiver;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mKillReceiver = new KillReceiver();
        registerReceiver(mKillReceiver,
            IntentFilter.create("kill", "spartan!!!"));
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(mKillReceiver);
    }
    private final class KillReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            finish();
        }
    }
}

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• Make your activities extend that BaseActivity.
• Whenever you want to clear the stack:

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Intent intent = new Intent("kill");
intent.setType("spartan!!!");
sendBroadcast(intent);

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