App Security with touch id only
When ios app is secured/locked with touch id, then on failure of touch id It asks for iphone lock code to open up the yahoo mail app..this can cause a security breach if phone gets lost and someone knew the passcode of unlocking the phone..
The feature of touch id should be exclusively for unlocking the app and if it fails then the original password option should come rather than the phone unlock passcode..
Calibrate this with apple and update the app with such a system that only the person who owns the phone or whose finger prints are added can open up the yahoo app..this will further tighten the security features of yahoo mail..
From a user of Yahoo mail since 2004