Apps are increasingly targeting homeowners who use green technologies--there's an app to monitor the performance of your rooftop solar panels and the Wind Speed and Wind Meter apps use the iPhone's built-in microphone to capture the sound of the wind (say, around your house) in order to get a wind speed rating. But a new app by turbine manufacturer Mariah Power, developed in conjunction with digital design company Create with Context, does more.

While Mariah's app also captures the sound of the wind--and then filters out ambient noise and spits out a wind speed rating--it one-ups the others by letting users create and share wind speed maps. Eventually, Mariah plans to build a geo-coded database of crowdsourced wind maps so users can find out if their town or city is wind power-ready.

When compared to readings of a wind speed-measuring anemometer, the app is accurate within 1.5 mph--but even that is a useful estimate for homeowners considering a rooftop turbine.

And naturally, if you buy that turbine after downloading the free app, Mariah hopes it will be their own small, low-speed Windspire turbine.