Do you know any free sofware for making 2d animations?
OpenToonz is pretty awesome
It even has bone animation, plastic morphing etc. very advanced stuff.
if you have your sprites already and just want to make a gif, krita and gimp are pretty good, but i´ll give krita the edge here, because you get some tools especially for animation, like onion skins etc.
Synfig Studio, Pencil2D
Has “Synfig Studio” skeletical animation?