I loaded Smart Talk onto my wife's phone (at the end of August). The install worked properly and I have received an email sayng it has been linked to the correct mobile. It also appears on "My BT" when I go to "Manage BT Smart Talk".
The app starts up but as soon as a number is pressed on the keypad it crashes returning "Unfortunately, BT SmartTalk has stopped." and offering options of "Report" or "OK". I have pressed Report but nothing has come back to my wife's email address.
It is a Motorola Moto G Android phone and is running on 4.4.4. I did wonder if she needs to update 5.0.