Select any number of zones by drawing a polygon enclosing them.
To draw a polygon, place a number of markers on the map by left-clicking on the map. Finish drawing the polygon by clicking on the first marker you placed.
If you are not happy with the polygon you created, click "Reset" and you can start over
Generating zone files
If you are using Locus, Google Maps or another map application that support the detailed zone outlines that you see on this site, you can just go ahead and generate the file. If you want to use another map application like OsmAnd that doesn't support this you might have to select the file output format "KML - POIs". In case you are using the detailed zone outlines in Locus and find it hard to spot the zones on the map, you could generate a POI file in addition to the detailed zone outlines.
If you want to process the zones in some way, you can choose the most basic output format "Plain - lat,lng". It will give you a file in which each row represents a zones latitude,longitude. If you just want a list of the selected zones, choose "Plain - Zone name".
Install a map application from Google Play that supports offline maps. I would recommend Locus. You could also import the KML file into Google Maps by creating a new map under "My places".
Using the zones in Locus
In the bottom right corner, you will find the measure tool. Open it up and click the ruler icon to start measuring. By left clicking on the zones, you will create a path. The total distance of the path will be displayed at the bottom of the measure tool window.
You can undo the last zone selection by clicking the undo icon or remove the whole path by clicking the "Remove all measures" icon.
If you are using a new and fancy browser, you can generate a GPX file containing the path. Click the "Create GPX route file" icon to download it!
This is a third-party product that is built using the Turfgame API.
If you find an error or have any questions about this tool, you can contact UrbanGeeks at the official Turfgame forum (http://forum.turfgame.com/)