I guess it's not a question of if but when this will happen. I think apple would just have to come up with a system/wizard on the phone where you enter the existing password for the app/website you want to access. It then sends the actual password to the A7 and stores it there. Then just accesses it with the touch id sensor whenever it is accessed. I imagine this is how they are tying itunes/apple id to the touch id sensor.
I guess this will be just a beta test for all things future with the sensor.
I guess this will be just a beta test for all things future with the sensor.