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 Taunton Interactive:
From the editors of Fine Gardening magazine comes Tomato Match, a free app that helps gardeners find a tomato variety that best suits their needs. Tomato Match prompts users to select what they want in a tomato (including type, color and use), then displays tomato varieties that meet those criteria, along with links for purchasing the seeds. Tomato Match searches a database of 99 tomatoesin every imaginable size and colorincluding heirlooms and hybrids, from old favorites to exotics. Finding the perfect tomato is the key to having a robust and flavorful harvest, and with Tomato Match, that dream will become a reality.