I'd like to create a character animation using Character Animator and then export it so that my developer can import it seamlessly into the iOS app. Any suggestions on the best way to go about this?
There are only so many ways you can export from Character Animator - as a movie file (with or without transparencies - lots of choices there) and as a sequence of PNG files. I believe all the Adobe internal file formats are proprietary, so I think they are the only choices you really have. I have not heard of any Adobe runtime for running the internal format on iOS devices (or any other devices) for example.
So the question really is do you want a sequence of separate PNG files, a movie file with transparencies (in Media Encoder filter encoders with the word “alpha”), or a movie file without transparencies. If you need small, I *suspect* a movie file without transparencies with a good encoder will get you the smallest files (you probably need to try fiddling around with the options).