[insoluble]

Official App Developer wage statistics, including both mean and percentile, in the US (for 2014) can be found here: http://www.bls.gov/oes/current/oes151132.htm

For generic Programmers, see here: http://www.bls.gov/oes/current/oes151131.htm

TL;DR: Programmers = ($44k to $128k); App Devs = ($56k to $149k);

PS: Sorry about not answering the actual question, but I thought this would provide some background to the discussion.