When I was dealing with the Services in Android, I found out that, we start a service whenever for the first time an application is created and started. But the next time, when we open the same application, then also the Service gets started.
 
So, I searched for this"How can i check that whether Service is running in Background or not?". And I found a great solution too.
- private boolean isMyServiceRunning() {    
-     ActivityManager manager = (ActivityManager)getSystemService(ACTIVITY_SERVICE);    
-     for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {    
-        if (YourService.class.getName().equals(service.service.getClassName())) {    
-            return true;    
-        }    
-     }    
-     return false;    
- }    
 
Here, "
YourService" is the name of the 
class of your service. This way you can check whether your service is running in the Background or not.