I've been looking for a lab multi-timer to track experiment runs (range from 5 min - 2 hrs). This is the best one I found so far, works quite well.
Some hidden functions (learnt from the GitHub):
Directly input minutes by typing numbers, edit by delete or esc keys; floating on top under the "Window" menu.
1. Save timers for later use after program quits (very important).
2. Being able to edit "title" for each timer, so multiple timers can be easily distinguished.
3. Stick multiple timers side by side, so it's easier to view them in one place (not important - can use app expose).