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 Telefnica Investigacin y Desarrollo:
Share your emotions and wishes with your Wish Tree!!Plant your seed and grow your tree, keeping your water and light levels healthy, so that you could send more wishes to the community.Explore wishes from other people nearby, watching their wish trees.You can mark as "I like", or comment the wishes. You can send private messages too, to help other people to fulfill their wishes. All, we can help each other to overcome our problems and make a better world.Interact and help other people has a reward! Get your social badges thanks to your interaction and comments.