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 PS Ventures:
Use your iPhone or iPod Touch as a wireless controller to control the iPad Game - Bash The Frog.The iPad game can be downloaded from the app store at http://itunes.apple.com/us/app/bash-the-frog/id465100747?ls=1&mt=8A frog will poke its head in the air. Move the controller device up, down, left or right to move the crosshairs on your iPad and tap the bash button to hit the frog. Hit as many frogs as you can in the allotted time. The iPhone or iPod Touch controller device must have a built in Gyroscope (iPhone 4 or later or iPod Touch 4th Gen. or later). You can play the game without one of these devices by tapping the frog on your iPad with your finger. It's just more fun to use an external controller. Choose a one minute, two minute or three minute game and see how your high scores compare against other players in the Game Center Leaderboards.