Hi Erik – we had some catching up to do for the Android app, so iPhone users wouldn’t really gain from updating the firmware: the currently available iPhone app is roughly equivalent to the new Android app. However, there are a few new nice-to-haves such as the addition of the COLOR tab which just displays the color temperature and green/magenta shift for ambient and strobe in large type. We also separated out the STILL and VIDEO exposure tabs into two. We added an EV tile, which would probably be useful for iPhone folks. In terms of functionality, there is not a huge advantage. We DO plan an iPhone update for Q1, 2019.
This blogpost covers the Android newness: https://www.illuminatiinstruments.com/android-app-illuminati-light-meter/