The iPhone can be transformed into an outdoor navigational device by loading a range of apps. As an example we’ve chosen the Viewranger app (others are available), and this has been combined with OS mapping also from Viewranger.
The iPhone has an incredibly high-quality screen, which makes this by far the best option for reading OS maps in detail. The sensitivity of the screen is also second to none, so again touch-screen functionality is a dream. But put on some gloves and the screen does not work at all; and as there are no buttons for scrolling, this limits the use of this unit to good weather.
Then there is the battery life, which is hard to estimate, but a few hours is probably the best with the GPS turned on unless you are very careful about how you use the device. Viewranger recommends a Power Monkey charger and an Aquapac waterproof housing for use with the iPhone in the hills. The Viewranger software is superb, but it is the iPhone that lets this system down in a hillwalking environment.
Software OS 1:50k GB mapping £128
Weight 134g
Size 11.5x6x1cm
Display 5x 7.5cm colour touch-screen
Power lithium rechargeable
Battery life 7 hours
Electronic compass yes
Camera yes
Website www.viewranger.co.uk