HERE Launchers are simple to use APIs which enable you to launch HERE applications from your own Windows Phone application, to perform services provided by those applications.
The API is compatible with Windows Phone 8 devices. Additionally the API requires the HERE applications implementing the services being present in the device. In case the API is used without the implementing application being present in the device, then the user will be forwarded to the Application store for obtaining the required application.
Currently there are three HERE applications which are providing the services implemented in the HERE launchers API: HERE Maps, HERE Drive, and HERE Transit.
Full information on the API implementation can be found from the official documentation for HERE launchers