Lately, I have been involved in a project called taxiplon.
taxiplon stands as a platform for taxi traffic, aimed at both taxi drivers and passengers. For taxi drivers, it provides them with an interface for acquiring all sorts of useful information about their shift, such as ship and airplane arrival times, pharmacies and hospitals open, etc.
For passengers, it gives them the ability to call a taxi just by pressing a button and selecting their pickup location. They can also see the driver approaching them, call him, and rate him. It also features a point system (as of version 1.1), and appointments with a driver of your choice.
taxiplon passenger application is compatible with iOS and Android. You can see more information here.
It costs absolutely nothing to download, and there are no extra charges for the passenger when making a call. A live demo is included. I suggest the next time you call for a taxi you use taxiplon. The more passengers are using the application, the more drivers taxiplon will be able to support.
And, remember, constuctive critisism and feedback are always welcome!