I'm working on an app which needs to display an overlay an top of everything else. It does this by creating a new UIWindow, and using makeKeyAndVisble to "take over" the screen. When it's done, it gives control back back to the original UIWindow.
Is this a bad thing to do? It feels like it's taking control of the app at a low level, which is generally bad; on the other hand, it's very straightforward to do, so maybe it's perfectly acceptable.
Opinions/experiences?