Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
ezgif.com - Ezgif.com is simple online gif maker and toolset for basic animated gif editing.
Grafx2 - GrafX2 is a bitmap paint program inspired by the Amiga programs Deluxe Paint and Brilliance.
Instagiffer - Create GIFs from anything!
Piskel - Piskel is a website where designers online create sprites or pixel art.
Gifox - Delightful GIF Recording and Sharing App for macOS