Actually I wrote this on App Store few days ago with a five stars rate, the strange thing is that my comment has disappeared. : )
I have tried all animation apps that I can found in App Store and made a chart to compare them. FlipaClip and RoughAnimator win my award. Actually I prefer FlipaClip more because of your good UI and the fluency of brush tracking (as a former graphic designer, an app's UI system is an important point that makes me decide whether to keep it or not.)
So please allow me to give you some suggestions and help that can make Flipaclip be better : )
1, Add more brushes or let users custom their brush. I guess a lot of people have given this suggestion. There are too few brushes, though they perform well. Also for my personally, the pencil’s pressure sense is too less.
2, Please add a function like “jitter correction” or “ smoother” ( I don’t know what’s the proper noun is ).
3, The Frame length. Every time I draw a scene which would stay still for a long time, I need to copy and paste paste paste paste paste paste ... so please please please let we can setting a frame’s continueing time. Oh and just setting the time by current layer but not the whole frame scene.
4, Two finger tap to cancel.
5, It would be better to export as mov and mpg and export single png image.
Hope these could help : )