The Due app does something like this.
Basically it’s 1 time fee + subscription.
The day you buy the app, you get every new feature for the next year and every previous feature.
If a new feature is added, you can subscribe for $5 a year. Upon subscribing, you get all new features since your subscription lapsed.
Blog post here: https://www.dueapp.com/blog/future-of-paid-upgrades.html
chris_st|1 year ago