Search the internet for iPhone apps
Connect your system to the internet and search for iPhone apps. You will find thousands of applications, but you have to look for the megaphone. It is ideal to read about it first before finding a free download link, as that will give you an idea of how to use it.
Find download link for megaphone
Go to Google.com and search for a free megaphone application on the internet. You will see numerous options available in front of you, but you have to pick the right one, as there can be a threat of virus in some of the links.
You can simply go to the following link to download this wonderful app: http://download.cnet.com/Megaphone-Free/3000-2094_4-10908257.html
Install megaphone on your iPhone
Connect your iPhone to the computer and install the newly downloaded application on your phone. Once the installation is complete, you can use it at any time in a party or somewhere you need to deliver a speech.
Plug in speakers to iPhone
If you want to make yourself heard, convert your iPhone into a speaker by plugging in stereo or amplified speakers to your phone. You can now launch the megaphone app and start making a speech.
Plug in iPhone into FM transmitter
In order to convert your iPhone into a wireless microphone, plug it into the FM transmitter and launch the megaphone application to have fun. You can use it at parties or functions, when you have to get the attention of the people around you. Moreover, you can also use it to make a special announcement.