Ulmon GmbH, makers of the City Guide 2Go offline maps, have made their 2Go series of apps for iPhone, iPod Touch, and iPad free downloads for the next few days (exact time span unspecified). These apps normally range between $0.99 and $1.99, and are designed for offline use with maps in Wikipedia type information about the sites. There are a dozen city guides available.

Ulmon 2Go City Guides

In addition to the 2Go series City Guides, the following two apps by Walking Audio Tours were introduced this fall, and are currently free. (These are both large downloads, and require a wi-fi connections). They are also designed for offline use with accompanying maps.

Walking Audio Tours

The 2Go City Guide apps are universal binary. The Walking Audio Tours are native iPhone apps, but may be displayed on the iPad in 2x mode.