I used to make Flash games a long time ago. Due to its deprecation, I promised myself only use free and open source tools to make games.

I loved Aseprite, distributed under the GNU GPL v2, but was moved to a proprietary license.

So I moved to LibreSprite, a fork of Aseprite. As they say on their website, LibreSprite is a free and open source program for creating and animating your sprites.

Try it!

https://libresprite.github.io