Unfollowers App that works?

So I had a very good reliable app called "unfollow pro" that I'd use to unfollow anyone who unfollowed me or who never followed me back to begin with. For the past three weeks though it has stopped "scanning" my account correctly and basically loads no information and is useless. I've tried to look for some other apps in the Google Play Store but it's tough. Some of them have nothing but 5 star reviews but they're obviously all bots which is super sketchy, and others that have genuine reviews are all 1 star. Does anyone have an app or similar service that can track down who unfollows/ isn't following you back? Anything helps!