I have an application that I would ideally like to run on all iOS versions, however I think Apple accepts apps only from a version and above (3.0 I think, but not sure). So
ok... strangely Im having a hard time verifying this... but it's my belief that you must build your app with the latest base SDK (4.0), but you can target an IOS version all the way back to 2.0. Ill continue to try to verify that.