SEAiq USA

SEAiq USA is a full-featured marine navigation app that automatically downloads NOAA and USACE charts for the US regions you choose. It provides waypoints, routes, tracks, night color modes, an anchor alarm, and weather displays (wind and isobar), along with chart measuring tools (EBL/VRM) and support for both raster and vector charts.

It includes WiFi-based NMEA and AIS, and offers a 7-day trial with full features enabled. After the trial, many features require an in-app upgrade. Note that background GPS usage can significantly affect battery life.