Megaphone transforms your iPhone into an instant Microphone, PA system or Megaphone when you plug it into amplified speakers. If you are at a party and playing music from your iPhone on the stereo, you can just launch Megaphone, and use your iPhone as a Microphone as you make a speech. Just plug in a stereo or amplified speakers into the headphone jack, launch Megaphone, and start talking. Plug the iPhone into an FM transmitter for a wireless microphone.
Note: 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."