Additionally, you can personalize the notification, like setting own colors and corner radius.
Once it's set-upped, Call Duration Lite waits for calls, energy-savingly, in the background.
Call Duration Lite is free. Therefore it's necessary to implement ads - what's even responsible for the permission "full Internet access".
The permission "read contact data" is needed to read out the duration of the latest call.
The permission "read phone state and identity" is used for detecting the phone calls termination.
The Call Duration fullversion is also available at the market. It's without ads, therefore it's also without the permission "full internet access - and it supports the developer. Additionally it can display the call costs.