GIFMaker for Mac - GIFMaker – Created a GIF from a video or Images is the easiest way to create an animated GIF on your Mac.
Giphy Chrome Extension - Respond to emails, tweets & more w/ GIFs in a jiffy
Giphy - Search all the gifs and make your own animated gif
PopKey for Desktop - Quickly share ridiculous GIFs from Mac or Windows
GIPHY Says - Turn your words into animated GIFs!
Vlipsy - Easily add your favorite video clips to any conversation.