Spanish version of the article is available at the following link.
1-click Taxi Button is a great solution to win the visitors from hotels, restaurants, bars and other public places in your city. Doesn’t require installation – just plug the power supply and your taxi is one click away.
Taxi Buttons are supplied with full warranty and data plan, all covered by the monthly subscription on each button.
Important: Taxi Butler now also works in the North American market though does not work in other countries with GSM 850-1900. More details here http://www.worldtimezone.com/gsm.html
Details on connecting Taxi Button with a particular service type are in the article