A colleague has since introduced the tool for me, and I use it whenever I want to do separate commits for uncommited changes, to avoid having to do the unkool git add <filename> && git commit dance. I also use it when I want to commit various hunks separately, and the tool makes that task real easy.
I was recently impressed by its equivalent functionality for the git --amend option. If you click on the Amend Last Commit radio button, it actually displays the commit message of that previous commit. I was surprised to see it, especially since on clicking that option, I quickly ran to the command-line to copy that commit message, only to see the message waiting for me, ready to be edited away.
Another feature I really like is that if you attempt to commit something without staging it first, instead of just complaining, if offers to stage and commit all in one click. Nice.
These functionalities are real simple, but they really make for a pleasant user experience.
When I checked its Debian PTS page, I got surprised by the glaring lack of bug reports, as well as a small number of Debian releases. I found it sad when I visited it's popcon page (which is linked from that PTS page), and got surprised by the low number of installations it has by Debian users.