Fastmail offers no such options.
Oh, really? Then what's the justification for not charging a single cent for free apps? It costs Apple just as much to host the Facebook app on the App Store as it does Hey (or any other paid app). This has always been such a disingenuous argument, and there's no justification for Apple's tax to be a percentage of the app price anyway. All this does is punish developers of high quality apps. Why should a developer of a $30 app pay $10 to Apple, but a 99 cent app pays only 30 cents, and a free app pays nothing? That's an insane pricing policy.
How does Netflix work on iOS again?
>>3.1.3(a) “Reader” Apps: Apps may allow a user to access previously purchased content or content subscriptions (specifically: magazines, newspapers, books, audio, music, video, access to professional databases, VoIP, cloud storage, and approved services such as classroom management apps), provided that you agree not to directly or indirectly target iOS users to use a purchasing method other than in-app purchase, and your general communications about other purchasing methods are not designed to discourage use of in-app purchase.
>Trying to join Netflix?
>You can't sign up for Netflix in the app. We know it's a hassle. After you're a member, you can start watching in the app.
And yeah, obviously you can sign in.
>Apple told me that its actual mistake was approving the app in the first place, when it didn't conform to its guidelines. Apple allows these kinds of client apps — where you can't sign up, only sign in — for business services but not consumer products. That's why Basecamp, which companies typically pay for, is allowed on the App Store when Hey, which users pay for, isn't. Anyone who purchased Hey from elsewhere could access it on iOS as usual, the company said, but the app must have a way for users to sign up and pay through Apple's infrastructure. That's how Apple supports and pays for its work on the platform.
https://www.protocol.com/hey-email-app-store-rejection