I've been using this tool for several years now. I think development has mostly stopped though it's still kept up to date with each macOS version. To be fair it's mostly feature complete anyway.
I've tried to transition to other GUIs but I keep coming back for the simplicity and ease of use. It's just a really well designed piece of software.
Edited title: The Git interface you've been missing all your life (if you use a Mac and can't figure out the command line) has finally arrived