A Java-based server application that runs on a Raspberry PI device. This software uses a PC-connector device to communicate with a Roco digital command center by implementing the XpressNet standard. Java server application sends the data, got from the client to the Roco digital center, and receives the broadcast messages arrive from the XpressNet network. These broadcast messages will be transmitted to the Android clients. The second part of the project is an Android mobile application. This can discover the server app on the local network, connects to it, fetches the current loco informations. The client can create a new loco (unique address, name, description, speed steps, photo), can modify a loco, and can control it. The communication between the client and the server app is plain-text JSON format. The client can turn on and off the loco functions from F0 to F20. We are able to control more locomotives attached to each other. They have to have the same speed-characteristics. Speed commands to double-header are common but other functions can be activated separately.