Animate2D (Studio Edition) available on Google Play. Is now Ad supported via Tapjoy. In light of this I've enabled save functionality so you can experiment with animation ideas in longer than a single sitting. Works on phone or tablet and a number of new features have been developed since you may have last looked at it.
Updated to version 1.6.3 with new graphing and smoothing features XY plot, Anchor Plot, Anchor into Parent Plot, in addition to relative angle, absolute angle, and rotate all plots with smoothing/shaping tool.
Copy paste delete range
Goto markers
Improved performance with new Frame Slider
New propagate functions that cut across frames
Graphing - abs angle, and relative angle
Bezier Curve Smoothing
Back button integration throughout
Total Offline usage Capability
Tweening - coming soon
Bezier Smoothing with Graphing tool:
For documentation on how to use it you can check out my blog
Development is moving fast.