I like to measure how many productive hours I have per day, but I don't want to see the time until I'm nearing the end of the day. This is akin to running: if you count every individual mile, you'll get tired a lot faster than if you just ran for a while and checked your distance at the end of day to hold yourself accountable.
I used to use https://www.online-stopwatch.com/, but whenever I wanted to take a break I'd need to open the tab and pause the timer. This was annoying because A) I might not be using a browser for anything else, and B) I'd see how long I'd been working up until then (i.e I'd inadvertently find out how many miles I've "run"). I wanted a small desktop app from which I could control my time measurement and not need browser access, so I wrote this small Electron app to help with that.
NB: I didn't put this on the App store, but you can access it yourself via this repo's releases.