Ulmon GmbH has City Maps 2Go Pro (iTunes Link) for the iPad in the iTunes App Store for FREE (regularly $2.99) for a limited time.
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.
This Pro version gives you life-long, unlimited access to maps and travel content covering all available destinations worldwide.