Ulmon GmbH has City Maps 2Go (iTunes Link) for the iPhone, iPod Touch, and iPad in the iTunes App Store for FREE (regularly $1.99) for a limited time. Deal expires June 2, 2013.

City Maps 2Go is the #1 App for smart travelers. Maps and content any time, even when offline. No network or WiFi required. Your solution when suffering from bad network coverage, slow connection, limited data volume, or high data roaming cost abroad.