Small apps that do one thing.
Independently made for iPhone. No accounts, no dashboards, nothing that needs explaining twice.
Three apps, so far.
What small means here
One job
If it needs a tutorial, it's the wrong app. Each one does a single thing and then gets out of the way.
Nothing to sign in to
No account, no profile, no password to forget. Open the app and it works.
Plain about money
Free where it can be. Where there's a subscription, you're told exactly what it unlocks, and what it costs, before you pay.