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 All Pro Apps Corporation:
Bird Tracking HD FREE has been optimized to be compatible with all of the high tech features of your iPadThe more birds you track, target and hinder from flight, the higher your score getsTouch screen capabilities make maneuverability fast and easyHD Graphics that fully utilize the amazing retina display built into your iPadGreat animated background music and sound effects that can be controlled even during game playWith Bird Tracking HD, you will never experience the same game twice, so there are hours and hours of fun arcade gamingChallenge your friends and family to see who will dominate Bird Tracking HD in your personal circlePlease be sure to check out our other apps in the iTunes App Store