I don't want a skeleton tool, i'd like something where you can transform a non animated picture into something animated with Special Effects, like the picture desintegrating itself, burning, or i don't know anything (fade to color, change color gradually)...
you put the sprite, you specify the number of frames for an effect, then it does it automatically for you.
It's cheap but still useful.
I wanted to show an example but gamemaker sprite file extension is gmspl -_-'
EDIT : can't find pixel pd, but i think after effects is the kind of program i need, but it's not free, right ?