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.
Harmonica Key is a music reference app for harmonica players. The app provides a simple interface for looking up common harmonica tunings, as well as overlay information about chords and scales. Players can choose to display information for different key scales and chords as well as change the root key of the harmonica. In addition, reference sounds are played when a note is touched to help players get the correct tone for bends and overblow notes.