Comment by matt_s

Use it as a way to differentiate yourself. One methodology I've seen used with installed apps is major upgrades require a financial renewal but those can be spaced out every couple years. I love it when I find an iOS app that is paid, without ads, without in-app purchases.

You just need to plan how that business model works and know that you won't have recurring revenue. Maybe that means you build companion apps, offer an optional subscription tier (often its cloud storage/device sharing based) or something like that.

I've thought of doing a subscription like service but its use case is more of a once-in-a-while style so an option there would be pay-per use instead of a subscription.