Try the live examples here.
Also see how we integrated the Routing and the Geocoding API to build a fully featured maps application called GraphHopper Maps
First step to play with the code is to get this repository:
git clone https://github.com/graphhopper/directions-api-js-client/
Now open index.html in your browser.
Currently the Map Matching API needs the togeojson.js, also included.
Integrate the APIs in your application
GraphHopper Routing API
You need the routing client.
There is also a different client developed from the community here.
GraphHopper Route Optimization API
You need the optimization client.
GraphHopper Isochrone API
You need the isochrone client
GraphHopper Matrix API
You need the matrix client.
GraphHopper Geocoding API
You need the geocoding client.
GraphHopper Map Matching API
Code stands under Apache License 2.0