GPL Section 7 Exception
As a special exception to the terms and conditions of the 
GNU General Public License Version 3 (the "GPL"):

As additional permission under section 7, you are allowed to distribute 
the software through an app store, even if that store has restrictive 
terms and conditions that are incompatible with the GPL, provided that 
the source is also available under the GPL with or without this permission 
through a channel without those restrictive terms and conditions.