The purpose of this basic bluetooth server is to allow clients(users) to exchange short text messages. Bluetooth is a very short range wireless technology so the communication process should be :
1) A user(transmitter) prepares a message on it's Andoid App to send to an other user(recipient)
2) When transmitter his close enough from the server, the message is uploaded and stored
3) When the recipient is close enough from the server, he will download the message and read it thanks to it's Android App.
Next level would be a multiple bluetooth stations network. In that kind of network architecture, users are the wires, they carry the information. So it's better not to be in a hurry !