"I believe they're all going to abandon the App Store," iFlowReader co-founder Dennis Morin told referring to his bigger competitors in the space, like Amazon's Kindle, Barnes & Noble's Nook, and Kobo.

"Apple is now requiring us, as well as all other ebook sellers, to give them 30 percent of the selling price of any ebook that we sell from our iOS app," Morin said. In a letter to users posted on iFlowReader's Website, the developers explain that Apple's policy, combined with  (which gives sellers a 30 percent share of the proceeds), makes iFlowReader unsustainable.

But whether the major e-book sellers really will follow iFlowReader into the night is anything but clear at this point.

What we do know is that, in February of this year, published a story featuring over an App Store rejection. Sony said it had run afoul of an Apple rule that prohibited iOS apps from selling e-books unless those transactions went through Apple's in-app purchasing process. That seemed to contradict the evidence: Amazon, Barnes & Noble, Kobo, and others--including iFlowReader--had been selling e-books via their apps for a while now. Had Apple suddenly changed up the rules?

When contacted by (and other outlets), Cupertino denied that this was new, :