ViewRanger provides access to thousands of trails from around the world. You can pick from street maps, aerial and satellite images, and terrain maps already made to follow, or even make your own. You can track your hikes, add photos and waypoints and share to social media. Cairn is especially useful when hiking in an area where cell coverage is limited or non-existent. You can download topographic maps for offline use, and also find spots where cell phone coverage kicks in. An especially useful feature allows users to set up notifications that will be sent to selected contacts if they are past due on arrival time.