FYI, Oproject has added a non-CPU sub-project "ALX". It pays a lot, especially when you consider it is just free additional credits.

Also, they added optimized, manual apps.

http://oproject.goldbach.pl/app_optymalizations.php

However there are no instructions (yet). I assume you need an app_info.xml, but I don't know if there is more to it or not. I haven't tried it out at all yet.

http://oproject.goldbach.pl/app_optymalizations.php