LightSpectrum Pro 9+

Some old-fashioned people think that a quality program should have no misspellings. So think about ‘cancel’ and ‘wavelength’, please. Aren’t you embarrassed by these errors?

First, the fact that it does what normally takes thousands of dollars in tools is fantastic. No, it's probably not nearly as accurate as pro devices to do this work and having said that, since I don't have access to pro-grade tools I cannot say how the accuracy of this compares. But now I have a way to quantify the various values of light sources, and most helpfully, I can compare them objectively.

This is certainly an app that every art, theatre lighting and photography student should own. Such a good learning tool to see how light sources and color interact.

For homeowners this tool helps sort through the spec's of the multitude of light bulbs at the big box stores.

I'm using this on an iPhone 6s with no problems.

My only complaints:
-The interface can get cluttered. Using it in landscape mode helps that quite a bit. In portrait mode, at least on my little phone, things get piled on each other. Wish it would run on my older iPad!
-The helpful explanatory tips are good, but I wish I could figure out how to shut them off.
-I wish I could take screen shots in landscape view.

Wish:
-Now if it had a way to measure flicker of bulbs! Don't care, make it a separate app or make it a purchasable upgrade for this one. I'd buy it!

I used to use a $2,000 light meter to measure color temperature when I worked in the film industry. This meter costs only a few bucks and is almost as good. The app description says it’s within 8% of the actual color temperature, which in most circumstances is sufficient. I tested the app in a variety of environments; I.e. outdoor sunny, outdoor cloudy, interior lights, balanced to daylight, cool white, etc. and it worked great. If you’re doing scientific measurements it might not be what you need but for film and video it’s pretty great.