This is a tile editor for 8 byte hex strings. Press "S" to save your created/edited image. Press "L" to load a string of hex bytes. In this case, 8 bytes. Press the space bar to change between Nintendo format and Solid format. In game ROMs, these kinds of images are used. Here's an image to get you started: FF9999E7C3C3DBFF
Broken as of 2023 March 08. Nintendo formats: *.gb;*.gbc;*.gba;*.nds;*.ids;*.ds;*.srl;*.3ds;*.n3ds;*.z64;*.n64;*.v64;*.fc ;*.nes; I figured out the byte orders, binary and other stuff myself.