If you have an Android device, there is an easy way to earn a bit of money to spend on the Google Play Store. Google has released an app called "Google Opinion Rewards".
It's a small app that will send you small surveys to answer in exchange for some credits in the Google Play Store. Surveys are small and the payout is quite interesting. Since I have installed it on my Asus Memo FHD 10, a few months ago, I had to answer around 10 surveys and was able to get around 5$ to spend in the store.
It's not much, but the payout always depends on the survey and your answers. Sometimes you'll get $0.16 and other time $0.75. Overall, you can get almost a free app or game each month.
Here's the link: Google Opinion Rewards - Android Apps on Google Play
Since the app is provided by Google, it feels a bit safer.
Leave comments about your own experience with Google Opinion Rewards...