Freebird is an app that enables you to earn cashback from things that you already do, such as taking an Uber or Lyft ride. The app is available for iOS and Android-based devices. Now they are offering a new signup bonus that gives you $5 off your first 5 rides when you use promo code 5FOR5. It should also stack with a referral bonus that gives you $5 off your first two rides. You can use my code S9629. Plus you get about $6 in rewards for completing a few tasks.
Freebird also has frequent promotions that give you even more discounts and cashback for rides that you can transfer to your bank. You can read more about the app here.