I just downloaded an app called Butt Trainer for my Android it looks very helpful
If you have YouTube just look up butt workouts or look up any workout app and they will usually give you a butt workout.
The best one I think is the Brazilian butt lift workout.Google it.cheers
If you have access to a gym, this workout program, although challenging, is very good for toning legs and glutes overall. I do it once a week.
http://www.muscleandfitnesshers.com/training/legs/smoking-hot-legs#.UxUBxgn2N2w.email
If you don't have access to a gym, of course squats, lunges, hip thrusts, wall sits, kickbacks on all fours, and supermans will tone things pretty well.