Mobile Performance Meter is an app that run in the background of your phone and reward points. You can get around $5-10 in gift cards per month per phone when using it. May require that your phone have a data plan. I have used the app on phones without a data plan, but some friends are telling me it hasn’t worked for them. I know their support team has told me they are very picky about not only what phones they approve but also locations and other factors to approve activating the accounts to start earning points.
You can earn anywhere from 10-30 points per day. I wait till I have earned 500 points to cash out for a $5 Amazon gift card. It costs more points per dollar if you cash out less than 500 points.