A free app for Android, by Elegant.

Unfollowers for Instagram, lost is an app that lets you to find out who followed and unfollowed you on Instagram. With just one touch, you will be able to do this. You can unfollow the ghost lost followers, remove them from followers list, and who does not follow you back. This is very easy and quick tool for you. You will just need to follow the steps bellow and you can now start using the app.

1. Login with your Instagram username and password, which use Instagram API for security2. Find the followers who do not follow you back and unfollow them