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 High Gloss:
Be one of the first to download the brand new Sound Grenade Pro with exciting new features.Remote Grenade - lets you target unsuspecting users from your web browser or another device.Target Ages - helps you select the best sound for your intended target. These sounds have been tested for maximum impact.All new interface - full support for Retina devices and military styled controls put you in the driving seat.Sound Grenade Pro 2 is the best way to annoy people. The sounds are so terrible that they have been known to induce nausea and headaches. It's an annoyance weapon. Be careful with who you use it on.Please note that there is currently an issue when changing ages while the grenade is on, this has been fixed and submitted to Apple to approve.