Retina Icon Set 2013.1
Here is a Free Retina Icon Set, which will help each iPhone or iPad application developer get his GUI in order.
The icons from this set can be used in navigation, tab bars and toolbars, as they specifically meet the icon guidelines for iOS applications. The icons are licensed under a Creative Commons Attribution-Share Alike license. You may use the icons for both commercial and non-profit purposes, as well as modify them.