So, I made this animation in a program, however, it doesn't seem to support exporting as a PNG sequence so I could convert it to a GIF. The animation is over 100 frames so saving each image one-by-one will take ages. However, it supports exporting as a "strip", which is like a movie film. Each picture in the animation has the same dimensions. Here's how the program's "strip" feature works.
The images in the animation are stacked horizontally, the first frame being the far left while the last frame being the far right. There are no gaps between frames, and the file name usually is "name_stripX.png" if the animation has X frames. If each frame was 32 by 32 and the animation had 8 frames, this file would have a width of 256 and a height of 32.
Here is some example output, each color fills in one frame:
Also, just to clear things up a little bit more, the program is called "Game Maker 8.0."