Tangentially related: Apple's general theme seems to be that's it okay for iPhone apps to be portrait-only or landscape-only, but iPad apps had better support a

Tangentially related: Apple's general theme seems to be that's it okay for iPhone apps to be portrait-only or landscape-only, but iPad apps had better support all four possible orientations (portrait, portrait upside down, landscape left, landscape right) unless you have a really good reason not to. It is not uncommon for Apple to reject an iPad app from the store for not supporting all orientations.