Bad Hair Day? There's an App For That: Freaking out about how frizzy your hair will be some days? Get the Haircaster iPhone App for 99 cents and style with confidence. Haircaster uses your location to find out the local weather and then analyzes how the humidity and temperature will affect your 'do. A little superficial and silly, maybe, but it could save you a little stress on days when you want to look fab and avoid frizz.