The download button opens the iTunes App Store, where you
may continue the download process. You must have iTunes installed with an
active iTunes account in order to download and install the software. This
download may not be available in some countries.
From Che-min Lin:
CardSwap is the easiest way to exchange digital business cards. It finds people nearby also using the app, and allows you to exchange cards with them using one click. CardSwap simulates how you would exchange business cards in real life. After you exchange cards, you can save them directly into your phone's contact list. If they don't have the app, CardSwap generates a nice looking email that you can send them. It's faster than digging through your briefcase, plus it saves trees!