Unfortunately, t-mobile does not support another WP at the moment and her old one broke, and she wanted WP that would support wifi calling - Lumia 635 was the only option.

This is discouraging me seriously from trying another WP!

And I am so happy to see what WP 8.1 is different than WP 8 like the close app and the notification

Unfortunately, t-mobile does not support another WP at the moment and her old one broke, and she wanted WP that would support wifi calling - Lumia 635 was the only option.