The quickest way I know of to launch the wallet app in "tap-to-pay" mode is to:
- lock the phone,
- double-tap the home button,
- activate Touch ID
Is there a way to do this without locking the phone first, to make it quicker?
Double-tap when the phone is unlocked will bring up the app switcher.
Note: This question is for phones with Touch ID, e.g. iPhone 6, iPhone 7