Sprite Fusion - Design your game with Sprite Fusion, the ultimate free online tilemap editor. Design 2D games with ease, direclty export to Unity Tilemap and Godot Scenes. Ideal for retro games!
OpenToonz - OpenToonz is an animation program that is a free software version of Toonz, the animation software...
Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
Synfig Studio - Just another WordPress site
LibreSprite - Free and open source program to create animated sprites.
Adobe Animate - Adobe Animate is a Flash, vector animation software.