let her remove it, she needs to see that you trust her, if she wants to cheat again then she will cheat regardless, i can see both sides of the argument but you just need to let her do her own thing and see what happens. If she cheats then you will find out, its very hard to keep something like that from someone (friends telling friends etc) and then you will know. Imo using the app to make sure that shes home means that you dont trust her to not go home and thats not a healthy relationship, obviously you would be cautious as she did cheat but if its going to cause this many problems between you then maybe you should leave it? personally i believe that once someone has cheated the trust can never fully be re-built and the relationship should just be ended, but good for you if youre putting in the effort to keep it going. So yeah, let her turn it off, give her that trust, and see what happens.