Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
VistaCreate - The VistaCreate is a free and global digital platform which is known for sharing, searching, finding, and creating great art.
Pixel Studio - The Pixel Art Is Always Fun
PaintCAD - Pixel art image editor, created for full keyboard control of image drawing without mouse using.
Piskel - Piskel is a website where designers online create sprites or pixel art.
Pixel Art to CSS - Draw and animate pixel art, export the results to CSS