Pixel Pix - Turn your photos into pixel art
Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
Voxel Builder - Design and edit 3D voxel models in your browser.
Pixel Studio - The Pixel Art Is Always Fun
Pixilart - A drawing app for delightfully retro pixel art
Piskel - Piskel is a website where designers online create sprites or pixel art.