Synfig Studio - Just another WordPress site
Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
Duik - Comprehensive animation and rigging toolset for Adobe After Effects
Grafx2 - GrafX2 is a bitmap paint program inspired by the Amiga programs Deluxe Paint and Brilliance.
Limber for After Effects - IK system for After Effects using shape layers as limbs for character animation
Piskel - Piskel is a website where designers online create sprites or pixel art.