runningInstance

The running service, or null when it isn't up.

Exists for AppFunctions, which are invoked into this process by the system with no guarantee the service is running - and no way to start it, since a location-type foreground service can't be launched from the background. Binding would be the usual answer, but a bind is asynchronous and an AppFunction needs to know now whether it can act. Same process, so a plain reference is enough.

Deliberately not a way to obtain the service: callers get null and must cope.