I've been hearing a lot recently about folks using the permissions of the APP to go along on first flights, and unfortunately, when I make a few inquiries, many of them have never looked at the new AC 90-116. Unless you go through the process outlined there, then "riding along" is not legal, nor in accordance with the Ops Lims - and if we don't play by the liberal rules we've been given, we are liable to have them taken away. I personally think that the APP is a great idea for a large portion of Phase 1 (I am not a fan for first flights, but we can all agree to disagree on that), and would hate to lose it.
For a great write-up on "doing it right", read Vic Syracuse's story in the July 2015 Kitplanes.
Paul