With this App you need never be lost in a National Park, nor chewing through data trying to find your way out. Avenza allows you to download a selection of free or paid maps, then view and use them offline. You can record your movements including speed and elevation, track it in realtime and export the data.  Drop place markers at your location and measure the distance to an end point to work out how far you are from your destination. Avenza Maps allows you to take photos and plot them in your map and search for points of interest. There is an optional Pro subscription with advanced features but the average nature playing family will find the free version more than sufficient. Remember to familiarise yourself with the features in this App before you set off and ensure you have a fully charged battery on your device.