UnFREEz, create GIF animations

Of great simplicity, is currently the only program that I know can create animations in GIF format, from a series of images (also in GIF format, other formats are not supported).
Its use is very intuitive: just drag images into the program window and when you are ready click Make Animated GIF.
Certainly not the features and functionality of programs such as Animation Shop fee (including the ability to vary the number of final colors, so have animations smaller), but for occasional use UnFREEz is more than enough.

UnFREEz