Obviously he/she altered the git history. There are many hacks floating around the internet to do something like this.

Yup, pages and pages of commits "Just now" without any content to them.

Maybe you can not copy other apps?

Your app is pure plagiarism. http://frontback.me/

Yes, I do not claim to be original. I do add other features to the app though, such as photo filters. And also, frontback is by far not the first app to do this. Just do a simple search in the app stores and you'll find lots of apps that do the exact same, much earlier than frontback.