Since October 1st, Roblox, the cross-platform game development and distribution portal, has achieved the #1 Top Grossing position nine times in the US on iPhone. Roblox monetizes by selling a hard currency, Robux, to users that can be spent across the Roblox portfolio of games.

Robux can be purchased on any platform, but prices differ between storefronts. Take, for instance, the catalogue of Robux hard currency packages on iOS (left) compared to that on the web (right) (hat tip to Matthew Ball for pointing this out):

On iOS, the only package available for monthly subscription is the $4.99 tier, which delivers 450 Robux per month. The same $4.99 tier can be purchased on web as a monthly subscription or as a one-off for 400 Robux. The next-cheapest package on the web is the $9.99 tier, which is the most expensive package on iOS (and delivers the same volume of Robux as a one-off purchase, but can also be purchased as a subscription that delivers higher value). Each subsequently more expensive package on the web is relatively cheaper on a Robux-per-dollar basis than the packages on mobile. Note that packages purchased on the web are not subjected to any mobile platform fee, even when those Robux are redeemed in the user’s account on iOS (or Android).
To state the premise: Roblox, a cross-platform product that happens to sell hard currency packs on the web that represent better value than those sold in its iOS app, is a #1 Top Grossing iOS app. This clearly puts Apple in a problematic position. But what makes the entire situation even more extraordinary — and, potentially, precarious for Apple — is that Roblox is a games streaming service that is allowed to operate without restriction on iOS.
In September, Apple established strict and cumbersome new rules for games streaming services on iOS, which previously were not authorized to operate on the platform at all. Under the new iOS guidelines, streaming services are only permitted on iOS if each game available for streaming by that service can be installed as a stand-alone app, with basic functionality, from the App Store.

Roblox is undeniably a games streaming app: clicking on a game icon from within Roblox’s games portal immediately launches that game, without opening another app on iOS. In other words: Roblox presents to users a catalogue of games that are substantially launched and played from within the Roblox app, without presenting the need to download any additional content.

Why is Roblox allowed to operate a streaming games service on iOS without abiding by Apple’s guidelines for games streaming services?
I believe that Roblox on iOS is a case where Apple’s deliberate ambiguity with the “Reader App rule” is creating clear inconsistencies with its enforcement of App Store guidelines. Apple ostensibly allows Roblox to offer larger hard currency tiers of better value than those available from within the app — and thus subject to Apple’s 30% platform fee — on the web because it is classified as a “Reader App,” and that app category is exempted from restrictions around IAP-based content access.
But the content being “read” in this case is interactive gaming content, which is not a class of content cited in the Reader App clause in the guidelines (eg. books, audio, music, video, etc.):

One might assume that the content precedent to which Roblox best conforms — and thus the set of guidelines most appropriate in governing its distribution — is that of a streaming app, which is covered under section 4.9 above. Why apply the “Reader App” classification to Roblox when the “Games Streaming Service” classification is so much more fitting?
But perhaps a better question: why did Apple determine that other streaming services, such as Stadia or Microsoft’s Project xCloud, would not be eligible for “Reader App” classification in the first place? There are a number of factors at play:
- The games streaming services from Google, Microsoft, et al feature content that could otherwise be available as direct-download apps on the App Store, whereas Roblox games are only available from within the Roblox storefront, having been built with the Roblox game development platform;
- Roblox features one-off purchase and subscription IAPs inside its iOS app, even if it tacitly encourages users to purchase hard currency on the web for greater value;
- Roblox is frequently a #1 Top Grossing app.
That last point is important: I argue in The future of mobile content platforms that ubiquity and popularity reverses the vector of dependency between content creator and gatekeeper. In other words: who is hurt worse, in the long term, if Roblox is no longer available on iOS — Apple or Roblox?
That the mobile ecosystem is evolving in this direction could pose significant problems for Apple. Apple’s enforcement of guidelines, especially as those guidelines change to accommodate new forms of content interaction (eg. games streaming) or to certify certain use cases (eg. the Reader App clause), are becoming conflicted. Under increased regulatory scrutiny, Apple may have to justify why an app like Roblox is allowed to stream games and offer discounted web-based IAPs where others aren’t.