Shopkick, which pays you to walk into stores (I'm not kidding.), scan items and make purchases has updated its app several times, with the most recent update today. It has surpassed Checkpoints as my favorite of these types of apps.
Should you decide to join, feel free to use my link. Note that I may get points if you sign up under my referral, so I appreciate it. I'm not sure what the current sign-up bonus is.