Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
Microsoft Paint - Paint (formerly Paintbrush) is a simple, ultra-basic graphics painting program that is included...
Lospec Pixel Editor - Free online pixel art program. It's easy to use, intuitive and unobtrusive.
LibreSprite - Free and open source program to create animated sprites.
Grafx2 - GrafX2 is a bitmap paint program inspired by the Amiga programs Deluxe Paint and Brilliance.
Mtpaint - Mtpaint is a simple painting program that will allow you either start new drawing project or carry own the existing drawing work that you have saved from the other paint and drawing programs.