I haven't tried it... I have a BlackBerry instead of an iPhone, so if anyone tries it, please let me know! It says you can experiment with different lighting styles without ever changing a bulb. The app is from GE Lighting, and it's called "Mood Cam". You can take a picture of an indoor space and change the mood or personality of the room by sliding the Moodometer. Then it shows you what types of fixtures and bulbs can be used to achieve your selected mood. Sounds like fun to me!
Residential Lighting also mentions that more how-to advice is on GE's website called "What's Your Lighting Style?" at www.whatsyourlightingstyle.com. The app is no charge on iTunes or through www.gemoodcam.com.
So if you try it, please let me know what you think of it!