Outdoor GPS Measurement

Uses your phone or tablet's GPS to roughly measure the distance between two points.

How accurately this measures depends on your surroundings - it will usually be accurate to within a 10 metres, but will be more accurate if you're in an open field with a clear view of the sky, and less accurate if you're in a city surrounded by skyscrapers. The error margin is displayed along with the measurement.

Like a measuring tape, it only measures the distance between two points - it does not measure along a route or multiple waypoints. Several different units of measurement are supported.




Usage

Simply load up the app, wait for a good enough GPS fix (you'll see the Accuracy entry under your current location get smaller and smaller until it settles down), and then hit "Set Base". The device will use that location as one end of the measurement.

Then, walk to the second point, wait for the accuracy to settle, and read off your measurement.

I wrote this to help me set out archery targets, and it should work well for similar outdoor uses like measuring golf shots (though there are better apps that have maps for that) or estimating the length of landscape features.

It will not work indoors - GPS, unfortunately, hasn't bridged that gap yet. I'd recommend buying either an ultrasonic or laser measurer for that, depending on how accurate you want to be.