GitUp is cool, I particularly love the graph view. It has almost no functionality though. You can't three-way-merge and resolve conflicts in it, nor browse the file tree for any given commit, nor compare any two commits.
True, it doesn't do everything, but it really hits the sweet spot for me. I wouldn't say that it almost has no functionality. To me, it has surprisingly much. It's just that it does such a good job of keeping the interface clean, that it can appear as if it doesn't do much.
It is the only git client I know that makes polishing the commit history (i.e. moving commits around, splitting(!), rewording, editing) pleasant. If only it was available on Windows too...
Have you tried Magit?
Mac Only...
Yeah, I also compared against GitUp, which I use currently, and I think I'll be sticking to it.