I have yet another suggestion for a feature that would be very useful and, I think, possibly quite straightforward to impliment.
When animating in the traditional way, with pencil and paper on an animation disk, one will often add or remove drawings as the action one is animating progresses. This is one of the advantages that hand drawn animation has over, say, stop motion. You can do your drawings in whatever order you like, and you can go back and add details and secondary animations as often as required.
To replicate this flexibility in FlipaClip, you could add a Bookmarks feature.
As an example; if I had an action that was made up of nine drawings from frame 12 to frame 20 and I wanted to go back and add a secondary action (maybe a cat's tail swinging as he jumped onto a wall), I would start by making my first drawing on frame 12 and then my last drawing on frame 20 (these are known as 'extremes' or ' key drawings'). Next, I would probably make the halfway drawing on frame 16.
I would at this point only have three pieces of paper on my drawing board, and I could easily flip them as I drew to check the animation. Of course, currently in FlipaClip, I would still have all the other drawings inbetween, making it difficult to flip my three drawings.
If I could add bookmarks to frames 12, 16 and 20, and have Flipaclip completely ignore all the other frames whilst the bookmarks were active, this would replicate the traditional technique I've outlined. Then as I added my inbetween drawings, I could add and remove bookmarks accordingly. Then, when boookmark mode is deactivated, I could playback or flip the animation as normal.
It's actually quite a simple idea, so I hope my post isn't too complicated! I think this feature would certainly improve FlipaClips already excellent standing as the ONLY traditional animation app for Android.