Why can't I subscribe from the iPhone or Android app?

Subscriptions are available through the web app only at app.stables.cloud. Apple and Google require apps to use their own payment systems for in-app purchases and charge a 15–30% commission. By handling subscriptions through the web, we avoid that commission and can keep prices lower.

This is the same approach used by services like Spotify and Netflix. You subscribe once on the web and the subscription works across all your devices, including the iOS and Android apps.