The ripme.jar tool which was always awesome hasn't been able to download redgifs for a while now. I don't think the ripme project is being updated either. Hasn't had an update in a long time now.
ripme was awesome for a few years. there's even a fork which was better maintained for a short bit. but its usefulness for twitter and reddit has gone to 0 over the last few months. nothing for those platforms that i know of currently (cli tools)
I'm using 1.7.95 version of the tool(I'm guessing this is fork). It works with twitter still, also works with reddit, but it just doesn't do redgifs, which is a bit annoying as it's the only video embed for reddit now.
Really late to the party and I hope I don't step on any toes with this shameless self promotion, but I wrote my own downloader that covers a lot of the sites that simpcity uses. I mainly download reddit users so it works for reddit and redgifs really well. If you are interested here is the link to the thread