Well, basically the title. I love trying out new apps across the whole ecosystem, but searching for them in the App store is not fun, and a bunch of apps I have used I found by accident in some posts or comments on the web.
So, the question is, what apps that are not widely known you use and recommend? Mac, iOS, iPadOS, WatchOS.
From me: WatchOS: TimeGlance that serves as date and time complication.
iOS/WatchOS: Duffy that serves only as a glanceable steps meter, with no fancy additions that many apps there have, and simple clean complications in watch.
iOS: Ermine, mainly serves me as a calendar widget that is better than the built in one, showing dots over the days that have some events and highlighting holidays.
iOS: Wristy, a widget to show my wrist temperature (requires Watch 8)
MacOS: Numi, a somewhat “natural language” calculator.
MacOS: Warp, a rich wrapper on the terminal.
Sounds like you haven’t tried Strongbox yet. Uses a KeePass2 database as the backend and integrates into Apple’s auto-fill system. So works everywhere where Apple’s built-in password manager works. And you can use the same database with KeePassXC on other platforms.