The website/app is at https://rwt.to , and an example route search is; from "Milky Way, Johannesburg" to "O.R. Tambo International Airport".
I should note that I've had a look at geocouch and it didn't fit my use case, I'm not doing trivial 'find my 3 places near [y,x]' queries, but am traversing a pseudo-network of routes to calculate directions. Neo4j also wouldn't have worked in my case. TokuMX is based on MongoDB 2.2 as far as I'm aware, so them too.
Also, I used to work for MapBox, and I know we did one project on mongo which I was not involved in, and afterwards we built everything with CouchDB (which is how I got acquainted with it).
For the geo stuff we actually used a lot of sqlite and to a lesser extent spatialite. We would pre-calculate things and build them into the rendered tiles in mbtiles format, or stream the point/polygon data from the couch database for realtime client-side compositing.
But yeah, routing is pretty high level stuff. I think they are only now putting the finishing touches on their openstreetmap driven routing system many years later.