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 The Jogye Order of Korean Buddhism:
Templestay is a programs to allow locals and foreigner to experience Korean buddhist monastic life and refresh body and mind in Buddhist temples surrounded by unspoiled area of serenity. Korean buddhism is the spirit of Korean culture root. You can experience the Templestay application indirectly and find divers information about the Templestay program through mobile phone. The menu bar consist of 5 menus : What is Templstay, Etiquette, Temple Information, Gallery, About Templestay Wherever and whenever you can experience "A Journey in Search of my Ture Self" through the Templestay Application.