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 Runner Apps:
This is a complete walkthrough guide of the video game The Legend of Zelda: Ocarina of Time. Use it to find your way through the entire game. Carry your iPhone or iPod Touch with you while you play, and pop it out of your pocket and open the guide when you get stuck. A great companion app. - Organized - Some come with maps - Allows offline viewing - No more searching online for tips, hints, guides - No need to zoom in and out - Icon with the actual game graphics, making it easy to find on your device - Designed in rich text, meaning graphics and video can be added in later updates!