From the review: "the top question readers ask me, 'How can I interface my boats’ systems to my iPad?'" We agree this is very important. In fact, SEAiq apps are the only charting apps from the review that interface to boating systems using NMEA and AIS over WiFi. The Garmin and RayMarine apps are limited to connecting to their own systems using the companies' closed protocols: if don't have a Garmin or RayMarine chart plotter, you are simply out of luck.
Also from the review: "SEAiq Open is unique for allowing users to install their own charts, including S-57, S-63, and CM93 charts, which means that you don’t have to purchase the same charts you’ve already bought a few times over."