Try perfect player.
I did this with VLC but I mainly use it on my pc
Image Machine. It definitely allows you to create groups however as you will see, there are other issues with it such as when you mark a movie as a favorite, it will appear multiple times in your favorites list based on the different categories it appears under.
I suspect it's the one you write yourself. I don't think this exists. You can pay for TiviMate and make as many groups as you like, call them what you like and move or copy what you want to them.