I also found both Nuticharts and MX Mariner battery killers. And integrating all the Android apps with NMEA is expensive and a pain. Marine Traffic is a supplementary navigational tool at best, it needs an Internet connection for starters...
The navigation systems for PCs are much more mature. NMEA data can be easily integrated. VNC/Teamviewer allow you to view and have a little control your PC navigation system from an Android device. The centralization of the navigation system seems more efficient and less error prone than importing/exporting etc.
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