I‘m using Due on the iPhone. It can be purchased per one-time payment and won’t get new features added then (bugfixes are still coming) but that’s fine since there are not so many new features. Plus, it syncs to the Mac (additional purchase needed).

Heh, funny. Tbh, I do not like the fist fights, they feel weak and clumsy, but this time I won on the first attempt. At least.