I made this for a really minimal version of daily time tracking. The touch bar turned out to be a great place for a stopwatch: tapping is easy, and you can easily check if it's running or not - even in fullscreen mode.

More info in a little blog post: https://www.alexzirbel.com/touch-bar-timer

It's open source, code here: https://github.com/azirbel/touch-bar-timer

Finally, thanks to Pixel Point for their Mute Me project, which was the starting point for this codebase. https://muteme.pixelpoint.io/