This app was mentioned in 2 comments, with an average of 1.00 upvote
didn't look to me like they update there social media much. last few vistior posts were about folks not getting there paypal payments as well.
not a bad concept overall.
edit: here's the android version
All of the sites I use are listed here.
Some notables that you didn't mention are Survey Village (Non-Ref), Purkle, Serpclix (Non-Ref), Voxpopme (Non-Ref), and Rewardia (Non-Ref). There are others too, but those would be the biggest omissions. Prolific too.