Nowadays many devices comes with fingerprint scanner. However in iPhone 7, many users don't know but they can add more than one fingerprint scanner. This is very simple and does not take much time. In fact many devices are there which allow you to register up to five fingerprints, so whenever your mobile fails to identify one, then you have the other option as well. Here is how you can do it.
iOS (iPhone and iPad)
Well, in order to register another finger click on the settings app, you have to select Touch ID & Passcode, then enter passcode and finally add new fingerprint.