Applying a promo code from a friend referring you to the app, or from a promo on the radio is easy! Tap the three lines in the upper left corner to reveal the app's menu:
Once there, tap on "Profile," to get to the next screen:
Tap where it says, "Edit," next to "promo code," and you'll be given a field that allows you to input the code:
Click HERE to access your profile page within the app.