Android : How to create a shared core service for multiple apps in Android

I intend to create a core service that can provide information (data from its database, GPS information) for many applications. It should run in the background and when an application needs information from it, it provides.

However, there are some questions to be answered:

1. Can a service "application" exist without creating an Activity and starting from it?


2. How can it be installed? Can a service without an application be put in Play Store? Or should the application that will use it, install the service?


3. Can a service provide information for many applications by using it as a content provider?

The main reason to create such a service is to optimize the resources. I want to get GPS coordinates only once and when 2-3 of my applications need the current location, they would get it from that service. If there is a better way to achieve this, please give me suggestions.