Apple is now rejecting apps that make use of Dropbox’s file synchronization feature, but not for the reason you might suspect. Instead, it has to do with the fact that Dropbox sells extra storage tiers through their website, which most apps link to in order to have new users sign up. Apple, it appears, sees this as breaking their rule that no app may sell a service or good that isn’t also available through in-app purchase, where Apple can take off their 30% cut.
The issue arises from Dropbox’s forums, where developers of various apps have recently been complaining about this turn of events. Dropbox powers numerous iOS text editors, along with various other types of apps that depend on syncing files back and forth, and prefer a more open approach than iCloud currently provides.
The first report was made four days ago, but more recent reports have been streaming in through the forum thread. One developer posted a screenshot of the email he was sent by Apple’s Developer Connect, which clearly shows that the issue is over the fact that Dropbox includes the link to sign up for a new account, which takes a user in to Safari. From Safari, a user can potentially click in to the “Desktop” version of the site, and navigate to the page on Dropbox which allows for customers to buy more storage space.
At this point, it seems that Dropbox will be forced to change the design of their mobile sign-up page to comply with Apple’s rules, though no official statement has yet been issued.
Update: Dropbox has already released an SDK update that should fix the issue encountered by developers, but the problem seems more widespread. It seems that apps that even link to a webpage where users can sign up for an account, but which also has the risk of the user purchasing some service through the web as well. It seems that Apple has decided to play hardball, and they’re taking it to an extreme at this point.