We've been working on getting our app to work properly with all the changes in iOS 7. Particularly the colors and layouts of things. But these changes are still in development.
The version of our app in the app store has none of these modifications. When testing locally, it works on iOS 6 fine and looks horrible on iOS 7. Yet, upon downloading it from the app store and installing it on an iOS 7 iPad, it seems to work just fine -- just as it used to in iOS 6 (!). We are wondering if there is some "compatibility flag" that the app store folks can switch, which means "not ready for iOS 7 -- use compatibility mode"? I'm not sure how else to explain this. Wondering if anyone else knows?
Our app: http://appstore.com/cedarssuite
Summary: running via the simulator on iOS 7 or on a development iPad that has iOS 7, the app looks horrible. But downloading the approved app store version and running on iOS 7, it works just fine. Why?
A note: This is no longer correct. Since February 2014, Apple only accepts SDK7 builds
That's normal. all the old apps work fine on new iOS versions since those app. Base SDK set to that old version. in your case (iOS 6.0). They will run using old sdks. But, when you built with the new sdk (Base SDK 7.0) they look horrible as you said and some times they crash. because of layout changes and controls behaviours in the new iOS.
You are only asked to build with the new sdk to take advantage of the new features.
keeping your app. built with the old versions doesn't seem to have disadvantages other than new features. since apple still accept publishing apps with old sdk back to 4.3.