From Forum Nokia Wiki

• The Journey is the world's first mobile adventure game. In the role of a detective, you uncover a thrilling mystery. Like a real detective, you can't do that by sitting around at home - you now have to walk around in your real surroundings to get to the different locations in the game!

Developed by Mopius (Andreas Jakl) and Freeware, Source code available under the GPL-license.