This is a plugin to be used with the Bluetooth SIM Access Profile app, see http://android-rsap.com/.
It's not a standalone application!
The plugin enables the usage of contacts from phone memory instead of SIM card.
It highly depends on your car navigation system. First ensure proper working of the Bluetooth SIM Access Profile app. The plugin supports only protocol data units intended for GSM applications (APDU with instruction class A0).
Modern car navigation systems may use different protocols, i.e. systems with UMTS/LTE support. On such systems the plugin may work, but it's not guaranteed. There is no plan to support further protocols.
With the current version of the plugin you are not able to create, modify or delete phone contacts using your car navigation system. Anyway, most systems won't support these actions.
If you have questions or problems, please contact me via email.