Good basic functionality – a full standalone navigation app – and plenty of advanced options as well, but each one incurs a fee.
Transas iSailor marine navigation app for iPad and Android
Here is another very well developed and easy to use app offering a great range of features, but for Android users, read the Google Play store information carefully, regarding which devices will work and which won’t.
Zooming is quick and at high level zoom, the details are crisp and of an appropriate size. This app allows easy waypoint and route creation and has a well set up navigation sidebar. Route tables can be viewed via the sidebar while a course is active, which is great for racing. The alarms menu covers anchor watch, waypoint arrival, loss of GPS signal and low battery.
iSailor offers more advanced features, however unlocking each one will incur an extra charge. Weather, tides, and sailing guides all have associated one-year subscription costs, and although NMEA integration is available, there is a fee for each stream of data. An internet AIS feed is also available.
This app definitely lends itself to being a standalone navigational device, but the pricing structure is not straightforward, so tot up the cost of any desirable extra features before committing.
For Navigation this app has it all and is easy with really well thought out meus and representation of data. However be wary of the hidden costs, chart folios are small and unlocking all NMEA data channels will cost over £30.