My Dad and I just posted a new video on the Geerling Engineering YouTube channel where we explored the tallest radio tower in the St. Louis metro area, the so-called 'Supertower' that has a 10-station combined dual FM antenna system (dual 4-bay FMVee by Dielectric) at the top:
tl;dr: Great-sounding, reasonably-priced microphone, purpose-built for the smartphones and tablets, with few downsides.
The iRig mic was introduced in 2011, and promised to be one of the best ways to get sound from your mouth or instrument into the iPhone 4, iPod Touch or iPad/iPad 2. Since then, it has been tested to work with newer iOS devices like the iPhone 5, and many Android phones. I've updated this review (in 2013) to reflect my more extensive testing since I originally reviewed the microphone in 2011.