Quite timid, but I do like to look at the forums on occasion.
I wrote a script for Aseprite which takes the selected pixels (or the entire image)
and encodes it into PICO-8 GFX format, such that it can be pasted in the sprite editor or the BBS.
// i couldn't figure out how to arrange it in a cleaner layout, sorry
The script, and instructions on how to use it, can be found here: asep8 git repo