Thanks! I'm glad you like it.
I think there might have been a little misunderstanding in my post. This is not a replacement iPhone icon for the Omnifocus iPhone app.
This is an iPhone-like icon for the Mac Desktop version of Omnifocus.
Regardless, removing the shadow is trivial, so I've done just that, and made a new .icns file for you to use however you want. Preview is also attached.
http://drop.io/f2qrsdw