The flexibility of the iPhone platform is allowing for a broad variety of tools to be developed for it which intend to address issues of interest for colorblind people such as myself. While I still don't own an iPhone (and don't intend to get one), this is another tool that can identify colors, simulate color blindness and provide color matching and coordination features.
HueVue performs a number of handy functions with an a easy to use interface. It can identify colors as well as try to alter colors to simulate colorblindness or compensate for the colorblind user. While those features are nice and not that uncommon it also has some unique features designed to assist with color coordination and color matching. Overall, if you're looking for a utility like this for your iPhone HueVue is another one worth considering.
To learn more about HueVue's wealth of features and its creator I'd definitely recommend checking out the HueVue website.