http://go.tagjag.com/freeapps - From free Xbox, Groupon, Amazon, iTunes gift cards to free time on T-Mobile, Verizon, or AT&T, if you didn't catch Free Apps when I first mentioned it, tap this link on your iOS or Android device. Been using it safely for about a year now. For the sake of completeness, I also use these programs:
There's also AppTrailers (iOS and Android), and it's easier to get points with since you just watch a video instead of download an app, but AppTrailers itself is pretty terrible. Worth suffering through it to me, though. It has given me a free game (PC/PS3) every month this year!
+Synyster Emmanuel Check out AppBounty. It's international, and operates on the same premise as FeaturePoints. The people that run AppBounty are nice folks, too--they even added Xbox points as a redeemable prize, at my suggestion.