I just found out that since the iOS 8.3 update, Apple Pay can now work similarly to using it on the Apple Watch. You can now scan your fingerprint before you go to make a purchase so your device is ready to pay! Just go to the passbook app and pick the card you wish to make the purchase with. You can then simply place your finger on the Touch ID and it will be scanned and you'll be prompted to "Hold Near Reader to Pay" This is essentially activating the NFC chip for use in an open window of time rather than only when you're holding it to a terminal. This feature is handy for those who have had issues with their finger scanning while holding it up to a reader to pay, which causes some stress and holds up the purchasing process.