Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
Stickman: Draw animation - Stickman: Draw animation is an animation editing tool that allows you to create your own animated movies in a few minutes.
Pixel Art to CSS - Draw and animate pixel art, export the results to CSS
PixelArtPaint pro - PixelArtPaint pro is a great pixel editor app that allows you to create and edit pixel art on your mobiles.
Piskel - Piskel is a website where designers online create sprites or pixel art.
ibis Paint X - Drawn with + ibisPaint