A free app for Android, by Lightspeed Research.

The purpose of this app is to make it easy to earn rewards for participating in a mobile usage research study. You can earn points by simply downloading and installing the mC+ app on your Android device. Once you’re invited to participate, you will be asked to complete some simple tasks in the app. You will be using your device to complete these tasks and to access the Internet. The app does not require regular interaction or usage for you to earn rewards. It runs in the background, meaning it won’t take time out of your schedule.