When comparing Ungit vs Sublime Merge, the Slant community recommends Ungit for most people. In the question“What are the best Git clients for macOS?” Ungit is ranked 15th while Sublime Merge is ranked 20th. The most important reason people chose Ungit is:
Ungit is open source software available under the MIT Licence.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Free and Open Source Software
Ungit is open source software available under the MIT Licence.

Pro Cross-platform
Works on Windows, Linux, and OS X.
Pro Optional Integration with Modern Text Editors
Ungit can be integrated directly into modern text editors, Atom, Brackets, and VS Code.
Pro Web-based interface
Ungit is web-based, meaning you can run it on your cloud/pure shell machine and then use the UI from your browser.
Pro Fast
This is one the fastest client we've found for switching around them.
Pro Actual git commands are visible/editable
Most actions have an option where it will show the actual Git command it's going to run, and you can modify it in place. Very handy if you need to use some obscure option, and also good training for learning command-line operations.
Pro Easy for beginners
This helps to see more complexity and it's very easy to get started with.
Cons
Con Node.js dependent

Con Setup is not user-friendly
Ungit is distributed as an NPM package and requires git and Node.js to be installed on your system before you can run it. Ungit must be launched by running ungit
in a command line terminal.
Con Exposes git commands to your network
No authentication, if someone can communicate with your computer on the port this is running on, they can execute any git command they want on your repos as well as view your filesystem's folders.
Con Slim feature set
Con Dark theme behind paywall
The evaluation version is fully functional, but is restricted to the light theme only.
