Info.plist is a settings file for iOS applications, you can find more information here. The IDE interacts with this file (and with others, like the entitlements) in order to make it easy for you to specify settings for your application.
In this article I show you how to change the setting of our project which controls if our application is going to be universal (is going to work on iPhone and iPad) or just is going to be an iPhone-only application.
An iPhone-only application can also run on the iPad, but it doesn’t use the whole screen space, that is, the iPad “emulates” an iPhone and allows you to run the app at double the size.
A universal application run properly on both devices.
Here is the screencast: