[havaloc]

https://www.dueapp.com/ is what you're looking for

> Couldn't reminder apps implement "nagging" such that dismissed notifications are re-notified until some action is taken?

[Terretta]

Sold through SetApp, which shows one way to "alternate App Store model" for iOS/MacOS.

Setapp is a subscription service for Mac and iOS apps. For $9.99/mo, use Due plus more than 240 other apps. No extra fees, no ads.

[sleight42]

Really, I'm looking for a standard. Really, I'm looking for Apple to open that API to third parties as they should have long ago.