The project ‘De Rotterdam’ aims to provide the Municipality of Rotterdam with a solution to the problem its employees face, when needing to contact and meet fellow team members in the vast new environment of ‘De Rotterdam’ building. Employees there do not have a fixed workplace, but can everyday choose to work at any flexible workplace available. This makes it hard for employees to find their colleagues, especially since the building extends on 40 floors. The objective of the project is to develop an application for the smartphone devices carried by the employees that allows them to locate their colleagues with the help of Wi-Fi monitoring. To this extent, the possibilities of localizing a device within a certain subdivision of a floor area were extensively explored. Research was performed in various areas, including space subdivision, localization, navigation and visualization, which resulted in an integrated final product. An intuitive space subdivision is used coupled with localization techniques like multilateration and fingerprinting to provide the location of a specific user’s device. A network is extracted and overlayed on the subdivisions in order for the path-finding algorithm to output a navigation route. The latter is displayed on a 3D model of the building for the user to follow and find their colleague. The above have been achieved with the effective use of Libelium Meshlium Xtreme Scanners and the development of Python scripts, PHP, Android API, Unity game engine and MySQL database. The success rate at which a user is correctly connected to their colleague is satisfactory but it achieves much higher levels when a second area option is provided to the user to search for. The end-product application’s name is ‘Catch-a-colleague’ reflecting both on the purpose of its design and target users. We believe this app has the potential to make colleagues meet each other much easier.