Gpx Downloader requires you to have an android device with U OTG (U Host) feature. It can download gpx tracks from such devices: - Holux GPSport 245 (http://www.holux.com/JCore/en/products/products_content.jsp?pno=349) - Mainnav MG 600 (http://www.mainnav.com/portfolio/mg-600.html)(and probably some others similar to this two).Every time when you plug something in your U port android asks what to do with this device. If you have Gpx Downloader on the possibilities list it means that your gadget is compatible with this application.Gpx Downloader is LGPL licensed. If you want to leave some input visit: https://code.google.com/p/gpx-downloader/