On iPhone: Go to your native device Settings > General > Language & Region > iPhone Language > Select preferred language order. This should automatically change the language used within World Phone. If the newly set language fails to load in World Phone, restart the App.
On Android: Go to your native device Settings > Language and Input > Language > Select preferred language. This should automatically change the language used within World Phone. If the newly set language fails to load in World Phone, restart the App.
On your device, simply go to Settings > Privacy > Contacts to allow this option.
All calls made can be found in History menu of World Phone. Selecting the (i) symbol on the right of the call record provides additional information about the call including call duration.