I've had the Google Opinion Rewards app on my phone since November 2013. Since then I've earned $37.74. That isn't much, but I'm still a big fan of the app. Every once in a while I'll get a quick survey to take, so for answering a few questions, I'll earn around $0.10. Over time it adds up. I use the money to pay for apps or songs that I'd never pay for with my real money. I've also used the money to rent videos that I've watched on the plane or at home using my Google Chromecast.
Here's the link for the android app:
Google Opinion Rewards App
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