Had the app crash once when I had used every single power up (resulting in loosing one of each - I don't pay money for this game so I conserve these) and then crashed multiple times. You do not get a heart back so you are just wasting your time. I wouldn't play until they get it fixed. It's increasingly frustrating everytime that it happens. Please fix this so we can play - also you should give everyone some bonus freebies for this poor performing app