Google Play now offers Android users a two hour window to receive a full refund on a paid app purchase. This policy has actually been in place for some time, however, it was not listed on their website. The previous policy was 15 minutes.
You can receive the refund by going to the Play store on your device, click on the Menu, then click on My Apps, click on the app or game you’d like to return, and select Refund. You’ll then be given instructions on how to complete the refund.
Note that if the Refund button is not displayed, your purchase is not eligible for return. Also note that you can only receive a refund for the app once. If you decide to purchase the app again, you cannot receive a second refund.