Release a free app that requires a user to log in. In order to access the content in the app, the user has to log into a web browser with that account and pay directly via the developer's website. Amazon Kindle and Netflix kind of do this. With Kindle, you have to buy the books with a separate app instead of a website, and Netflix has the option to buy inside the app as well as outside.

Apple has rules against circumventing their billing system. Netflix gets to do it because the service works if you don’t have any iOS devices.

I’m not sure someone like Fortnight could get away with bypassing it. If they did it would only be due to being a special case due to pull. No normal app could get away with it, you’d get pulled fast.

IIRC you're just not allowed to programmatically open a web browser; you have to tell the user to do it themselves.

Amazon does it all of the time. You pay for content by going on Amazon.com and you view the content via an app.

This may work for Amazon only because their own brand is also directly known to the user, and a lot of users would also be visitors of their website. But for a newcomer trying to sell digital goods via an app, good luck

They may have some sort of ‘free pass’ due to their size/influence. It’s eqsy to say that Amazon’s content is meant for Kindles too, and just happens to work for the iPhone.

But if you have an iOS only app? Good luck arguing your way out of the rule.

Udemy works the same way. You can buy content either in the app store or outside and it still works.