Jeff Potter's APACView 2.3
A GIF loader which displays and saves GIFs in many Atari formats, as
well as "APAC" mode, which is a software-based 256 color mode.
It also views in red-only, green-only, and blue-only modes which can
be saved and viewed all together as 8 color (high res), 64 color (med res)
or 4096 color!!! (low res) RGB mode images using Jeff's ColrView program.