The "Download Now" link directs you to the iTunes App Store, where you must continue the download process. You must have iTunes installed in order to open the link, and you must have an active iTunes account to download the application. This download may not be available in some countries.
If you are living in Ho Chi Minh city, Vietnam or planning to travel to, this is a must-have app. It gives you details about the most exciting places, the best hotels, restaurants, bars. It also gives you emergency telephone numbers (fire, hospital, and police) and embassies' address as well.