ezgif.com - Ezgif.com is simple online gif maker and toolset for basic animated gif editing.
TinyPNG - Make your website faster and save bandwidth. TinyPNG optimizes your PNG images by 50-80% while preserving full transparency!
Instagiffer - Create GIFs from anything!
ImageOptim - Faster web pages and apps.
Gifsicle - Gifsicle is a powerful, simple command line tool for creating, editing, and optimizing animated GIFs.
TinyJPG - Compress JPEG images with perfect quality and file size