Bluetooth as Service and Sockets for communication with other Activity

We want a simple Android Java app that will perform Bluetooth communication as a Service with no UI. This app will talk to a remote device over SPP. It can connect to the remote device through its MAC id. This app will then communicate with any upper layer Activity through Sockets. We will actually be coding the upper layer Activity in Qt/Necessitas. This Service app will be in Java using Android API but it will much better if we can include the Service Java app also in Necessitas.