I'm one of the creators. This was built in 40 hours at Hackzurich 2015 (www.hackzurich.com) and combines the following:<p><pre><code> * The largest rent database of Switzerland
* A model of the train system of Switzerland
* A simple recommender system
* Google maps for name -> geolocation
* OpenStreetMap for the map
</code></pre>
There are some heavy calculations behind each query, so it takes about 15 sec to load. Furthermore, you need to like at least 3 apartments and dislike at least 3, before the system starts recommending.