If you want to tell which app serves pop-up ads on android home screen then below are the steps:-
1. The first is to visit the Android settings by going to Apps in the settings and then go to Manage apps.
2. Then tap on the recent app’s key which is located on the left of the Home button.
3. Now scroll downwards and open the notification panel.
4. Then remove all the Ad serving apps which permits pop-ups.