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 Hybrid Fitness:
The Hybrid Fitness application uses a working animated model that demonstrates all exercises from the hybrid Fitness database. The best feature is that the avatar is an animation of the human muscle-skeletal system, and highlights the focused muscle group in use. This allows clients have a clear understanding of the desired exercise they need to execute and which muscle groups are being worked. The user simply enters the number of reps performed and weight used and rates the exercise depending on its level of difficulty.