Pixel Art Studio - A purpose-built drawing tool for pixel artists
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
Da Vinci Eye - Learn to draw by using your phone to overlay images for you to trace