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 Giacomo Balli:
If you travel a lot and have many friends around the world then you need this app. This app is unique in the store.Donca is the first social app for iPhone that lets you know who you can hang out with in any place in the world.Open the app, let it find your location and it will tell you who's around. Once you select a person there will be an awesome panel from which you can get in touch.You can also manually select a location and add a trip with dates so your friends can know when you'll be traveling.