ezgif.com - Ezgif.com is simple online gif maker and toolset for basic animated gif editing.
Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
Instagiffer - Create GIFs from anything!
Shutter - Shutter is a feature-rich screenshot program.
Gifox - Delightful GIF Recording and Sharing App for macOS
Snipping Tool - Use Snipping Tool to capture a screen shot, or snip, of any object on your screen, and then annotate, save, or share the image