I'm using the iPad / iPhone app and there is nowhere for me to enter my promo code

The iPad and iPhone apps have been updated to enable you to enter a promo code when using them. Please check the app store to ensure you have the latest version of the app installed on your device.

Unfortunately, it is not possible to redeem student discounts (when available) on the iPhone or iPad apps at this time. However, you can redeem student discount (when available) via the mobile browsers on these devices.