Trackstar 
Trackstar is a GPX parser. Specify the path to a GPX file and it will output a GeoJSON of the track as a LineString. It currently works with Strava-exported GPX files.
How to use it:
Trackstar.parse("path/to/my_track.gpx") will convert your GPX file to GeoJSON. You can find your new file in export/my_track.json
Installation
If available in Hex, the package can be installed as:
Add trackstar to your list of dependencies in
mix.exs:def deps do
[{:trackstar, "~> 0.0.1"}]end
Ensure trackstar is started before your application:
def application do
[applications: [:trackstar]]end