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.
From Tourism Authority of Thailand:
Do you want to travel different?Thailand is going "GREEN". From the farming villages of Isan, Thailand's Northeast, to the pristine beaches of the country's South, the preservation of the environment, and the willingness to accommodate visitors interested in interacting more with local communities has become a significant trend.The official Green Tourism application is powered by the Tourism Authority of Thailand (TAT). The application contents comprise Green Destinations, Green Hotels & Resorts, About 7 Greens concept, and Contact Us. Features include: Map, Share or Bookmark your favorite destinations, hotels and resortsBecome a green traveler today!