It works well

I used this in Berlin a few nights ago. I needed a taxi for a 7am flight and was staying with a friend on a small side street. Figured my German was poor enough that calling to reserve a taxi would be an adventure. Within 5 minutes I had reserved a 5am taxi. He was there waiting at 5am. You can also easily see where taxis are waiting or what streets they are driving on, so you can hail your own when walking. Very nice.

QuasiMD about taxi.eu