Can’t cancel subscription
The classes are great. I mean it. The app more or less comfortable to use too. BUT. When you subscribe, there is no way you can unsubscribe on an app or web app, nor it is managed via Apple Subscriptions. And as the subscription period ends when payment can’t be transfered it tries many time after it. So that’t not the way too. Emailed the developer team, and I’m waiting for them to answer.