The European football championship offers many new ways of dicovering the cities hosting the tournment, either in Poland or Ukraine. One of interesting app I have found was Farol Warsaw. This seems to be a different approach and an easy way to visit a city when we know nothing at all about it.
you can try it here. The small price worth the money spent.
Other apps are also interesting to follow, such as tripadvisor for different cities, with recommendations from other users about restaurants, or booking.com for looking for a hotel.
Enjoy the Euro 2012