This study presents an interactive configuration tool that assists non-expert users to design specific navigation route for mobile robot in an indoor environment. The user places small active markers, called pebbles, on the floor along the desired route in order to guide the robot to the destination. The active markers establish a navigation network by communicating each other with IR beacon and the robot follows the markers to reach the designated goal. During the installation, a user can get effective feedback from LED indicators and voice prompts, so that the user can immediately understand if the navigation route is appropriately configured as expected. With this tool a novice user may easily customize a mobile robot for various indoor tasks.