From Pedagoguery Software:
A Smaller GIF is a program for reducing the size of animated GIFs without affecting their appearance in any way. It is often capable of reducing an animated GIF as most GIF utilities do not maximally compress their output. A Smaller GIF also serves as a full function animated GIF viewer.
Fixed a bug that could introduce data corruption to GIFs that use "Restore to Previous" frames
Improved colour reduction for GIFs that use more than 255 colours. A Smaller GIF makes no visible changes whatsoever for GIFs that use 255 colours or less (the result is pixel-for-pixel equivalent to the original; the compression is "lossless"), but for GIFs that use more than 255 colours, A Smaller GIF modifies the GIF to use 255 colours. The improvement introduced in version 1.22 reduces the visual distortion caused by colour reduction. Future versions of A Smaller GIF may allow users to employ "lossy" compression.