Sykora said Apple’s application programming interface in the iPhone OS software development kit does not provide a way to do the gesture, so he and Kaneko coded it themselves. The feature was even demonstrated in a promotional video the developers created for Web Albums HD through the iPad SDK.

“When we submitted it to Apple, we were stunned by their response,” Sykora said. “Apparently the tap and pinch to expand is only for native Apple apps.”

I don’t think the App Store approval process is going to be sustainable for the level of success Apple wants for the iPad.