The purpose of this document to introduce the structure, operation and use of the server-client application made for the LEGO NXT Robot. The first part of this documentation describes the applied technologies, the dynamics of the server and client software and the communication between the server and LEGO robot and between the server and the client. The second part of this paper examines the possibilities to expand the existing client functions from the developers’ point of view. It proposes a method to add new features, and shows the use of the software, the creation of workflows, the usage of the webcamera and the possibilities for direct controlling from the users’ point of view. The software is built on .NET 4.0 framework, and is written in C# language.