Rated 2 out of 5 stars
This is a two star addon I would gladly rate five but for the lack of one very important piece of functionality: you can't open/edit animations, only create new ones. Each time you close the window you'll have to start from the beginning.
The editor looks very glossy and competent, it's easy and intuitive to work with, and it certainly does its job creating animated pngs, but the inability to open/import animated pngs is crippling. This is akin to writing documents in office, saving them as pdf and throw away the actual document. Any mistake means start over.
Fix this and you'll have my 5.