Radius on Map lets you make a radius on a map easily and share a URL showing the radius via e-mail or text message that can be viewed with any browser. With this tool, you can lock a radius to your current location. In adition, you can share multiple radii in one URL. You can export your radii as polygons saved to a KML file to view in Google Earth or in other mapping applications. You can attach the KML file to an e-mail or save to iCloud, Dropbox, etc.
