Tile Studio - Complete development utility for graphics of tile based games.
IcoFX - IcoFX is an all-in-one solution for icon creation, extraction and editing.
Tilesetter - The tileset designing software.
Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
LibreSprite - Free and open source program to create animated sprites.
VistaCreate - The VistaCreate is a free and global digital platform which is known for sharing, searching, finding, and creating great art.