Dropbox has been popular with iOS developers because it allows users to share files created within their apps to other devices.
The online storage outfit's latest SDK, however, has caused Cupertino to throw its toys out of the pram because users who don't have the Dropbox app installed on their iPhone/iPad are instead pushed to Dropbox's website via the Safari browser.
This allows them to lick a link to the desktop version of the service, which allows them to buy extra Dropbox storage without Apple taking its usual 30 percent fee.
Apple claims that that any apps based on the new SDK are contravening its rules on in-app purchases. Developers pointed out that Apple was doing its best to kill off any commerce which did not take place within its walled garden of delights.
The Dropbox forum includes comments like: "Apple should reject all web browser apps because they can take you to a page that lets you purchase stuff."
ZDnet claims that Dropbox is in negotiation with Apple over the ban. Good luck with that, Apple has shown a marked lack of interest in co-operating with those who offer a rival service.