SEAiq

SEAiq is a full-featured marine navigation app.

It is the only marine navigation app that allows you to load your own charts in a variety of standard formats, including: S-57, S-63, iENC, BSB, and KAP.  It also includes the ability to automatically download charts from NOAA for the USA and download of raster charts based on satellite imagery.

Other features include:
* Waypoints
* Routes
* Tracks
* Night color modes
* Anchor alarm
* Automatic download and display of weather (wind & isobar)
* Chart measuring tools (EBL/VRM)
* WiFi-based NMEA and AIS

No purchase is required to use SEAiq to view charts.  All features are enabled during a 7-day evaluation period.  After that, many of the features require purchase of an in-app upgrade.

Continued use of GPS running in the background can dramatically decrease battery life.