Simply log in by entering your FRITZ!Box password, selecting one of your landline telephone numbers, and them confirm: your smartphone is ready for landline telephony. The FRITZ!App Fon guides you through the easy Configuration. The latest technologies mean that the FRITZ!App Fon works invisibly in the background no matter what the battery status. Thanks to support for Bluetooth headsets you can enjoy complete flexibility for everyday calling and for working from home. HD telephony provides for crystal clear voice quality. With the FRITZ!App Fon you benefit from the landline rates for many providers even from flat rate telephony. Make calls at home conveniently using your smartphone over your landline telephone numbers - anywhere in the Wi-Fi network of your FRITZ!Box.