I've been using this TAP Fireworks prototyping framework (based on jQuery Mobile)for the last few month - works quite nicely for simple animations.
(Some of the interactions are a little finicky in iOS7 - I need to find time to poke around and update jQuery Mobile and then send it back to the original creator.)
Anything else, I've been using the animation pane in Photoshop for simple GIF demonstrations (also, been really wanting to dig in deep on After Effects - haven't had the time though).
I've been using this TAP Fireworks prototyping framework (based on jQuery Mobile)for the last few month - works quite nicely for simple animations.
(Some of the interactions are a little finicky in iOS7 - I need to find time to poke around and update jQuery Mobile and then send it back to the original creator.)
http://unitid.nl/2011/03/touch-application-prototypes-tap-for-iphone-and-ipad-using-adobe-fireworks/
Anything else, I've been using the animation pane in Photoshop for simple GIF demonstrations (also, been really wanting to dig in deep on After Effects - haven't had the time though).