Answer quick surveys and earn Google Play credit with Google Opinion Rewards, an app created by the Google Surveys team.
Getting started is easy. Download the app and answer basic questions about yourself. You will then get surveys around once a week, although it may be more or less frequent. You’ll get a notification on your phone when a short and relevant survey is ready for you, and can receive up to Rs. 50 in Play credit for completing each survey. Questions can range from, “Which logo is best?” and “Which promotion is most compelling?” to “When do you plan on traveling next?”
Of course Google uses the Survey to target specific ads to you. But overall, the Surveys are simple and non-intrusive – you can even skip a survey and if you find it too irritating, just uninstall the app!
Android : https://goo.gl/dCgzT1