This is such an easy app for using GIFs and emoji anywhere. I have it set to launch at start-up and it's hidden in my menubar unless I need to add a cool new GIF. Once I figured out the best process for saving GIFs locally to then enter them into the app, I was settled on using Rocket for my everyday GIF sharing and emoji entry tool.
My first attempt to use this was in Atom. I tried typing out two separate emojis. In both cases, Rocket replaced the text with whatever was in the clipboard.