You-Get - Command-line utility to download media contents from the web
Gifox - Delightful GIF Recording and Sharing App for macOS
CONV. - Convert YouTube video to MP3, GIF or MP4
Giffing Tool - Giffing Tool is simply put: The fastest creator of high quality captioned GIFs available.
Softorino YouTube Converter - Download YouTube video & audio. Watch and listen offline
Instagiffer - Create GIFs from anything!