While working on the 2nd iteration of my MIDI controller Miwos, I needed a pixel font editor that supports the obscure Adafruit GFX font format, made especially for rendering text on microcontrollers. Most existing tools didn't work on all operating systems or were hard to use, so I developed the GFX Font Editor, a web-based app that can read and create the special font format, but also supports OTF export.

Thanks to Clemens Piontek for his font Vevey Positive, which I have been using as a basis for the Miwos pixel font.

Documentation avilable on GitHub