In 2011, we developed a web-based map client for mobile devices on behalf of the Swiss Federal Office of Topography (swisstopo). The application is based on OpenLayers and SenchaTouch and starts automatically as soon as a geoportal is accessed from a mobile device (iPhone, iPad, Android). The Geolocation API ensures that the map is centered on the current location of the device. A location search and the option to add further layers are also included in the exemplary client.