I had fun creating a web application that transforms any ebook reader into a high-visibility GPS navigator.
Here is a picture from a bike ride, note the difference in contrast with the bike computer and with a professional gps navigator (Garmin etrex legend)!
The GPS signal is taken from my phone (in my pocket). It communicates with the ebook reader through wifi. No software is installed to the ereader which is unmodified. (The navigator software is a web page that is opened by the ereader). The picture shows a Sony PRS T2, but it looks even better on a Kindle touch. I also tested it on a kobo aura, on an old ipad and on a pocketbook ereader. The software runs on android phones (I used a Wiko rainbow Jam with lollipop).
You can download the software files for the phone here: kindle-gps.zip.
The installation and run instructions here: readme.
Please don’t ask me to change it or to adapt it to iphones or whatever.. You’re welcome to change it yourself if you want. You are on your own if you use this software: no warranties at all! I decline all responsibilities, e.g. if it causes your local galaxy cluster to spawn a black hole that eats your homework or your home planet.
I thank Dave Schneider, who sent me his software for a similar project: all the nice parts in the code are his.