Bitsy Font Tool
With the release of Bitsy 5 came a brand-new font system. The new system is far more customizable than the old one: among other features, it includes a spec for a .bitsyfont format which can be used to make custom fonts. Since the format is plaintext, it's relatively easy to make custom fonts by typing them out in a text editor, but from a creative perspective, it's a bit hard to draw characters that way. To help with this, Fontsy provides a way to convert back-and-forth between .bitsyfont and .bitsyfont.png files, which can be used to draw fonts in a more traditional image editor.