Changing mobile horses in midstream?

[Graham Samuel]

I'm developing an app that is supposed to work on iOS devices - iPhones or iPads, so to keep a single code base, I need to set up the layout of the app at startup. This has been discussed before and I feel it's not so tough. I did a lot of similar stuff on Windows apps in the past, to cater for different monitor sizes, and even multiple monitors.

My question may be a nonsensical one, but is it conceivable that an app could start on one device and somehow be transferred to or woken up on another, so that the layout work would have to be done again during the operation of the device? This is kind of an extension of the issue that the orientation of a device (portrait <--> landscape) can change at any time (if the app permits it). I am just trying to cover for the idea that the working screenrect might actually change during execution, apart from the obvious 90 degree switch.

Graham