The Navionics Android app is the only nautical chart application that doesn’t require an Internet connection to work. The app also downloads maps on first start, without being connection to the Internet. However, getting the maps downloaded like this can take you a lot of time. So connect to Wi-Fi to download and decompress the charts in about 15 minutes.
Once the maps are downloaded, save them on a microSD card for use. Once in memory, these charts can be used any time, anywhere even when your phone is out of cell range. The app works great, charts routes very well, and has a clear interface. The speed and the screen change over time is quite good, and it tracks flawlessly with GPS.
The Android version of Navionics Marine Charts is more accurate as compared to the iPhone version. Though the features and functionality of both the versions are same. Navionics, when operating without cell phone signal, picks up better GPS signals.
The basic navigation functions work great on this app. Your boat is live on a chart and you can plan and navigate your course. You also have the ability to create, save and name, as well as rename a route. It's also nice to have live wind, tides and currents forecasts, when online. Moreover, it’s cheaper than any commercial tide prediction software so it’s worth the money. You also can export routes to Google Earth or via e-mail. The only let-down here is that you cannot import routes.
The app also lacks pinch to zoom functionality. You have to double tap to zoom or use the zoom buttons to zoom in and out of charts. Another bug that you’ll notice is that when you try to close the app, the GPS remains active. You need to kill the app in order to exit Navionics or else it will drain your battery. A simple exit button could have been a big help here.