Client Service

I need Simple mqtt client service, must start on boot and keep running while screen is off & phone is locked & app is closed. Also I need 1 activity to be able to stop the service and Set the topic to subscribe. The mqtt client will be connected to hard coded broker and will auto subscribe to the dynamic topic. Most important, Service must keep running and be connected to the brocker. Also, once the service recived payload, make notification. Should be Simple job for those who know how to create good and stable service.THANKS