The iPhone is more than capable of recording quality videos. But videos with low quality sound are not ideal. The iPhone Boom Mic is a cool add-on that lets you improve the sound recording capabilities of your iPhone. This is a small microphone that brings a professional touch to you audio recordings. It attaches to the headphone jack and does not add too much weight.
The iPhone Boom Mic offers two directional settings. It is so small you can carry it with you easily. It works for iPhone 4 and iPhone 4S. You will need 1 AAA battery to power it up. This will cost you $40 but will improve the quality of your audio productions. Useful for quick interviews and recordings on the go.