As a new Model S owner, I felt the need of a route planner for my Tesla which helped me plan my long trips using Superchargers. The in-car planner has its issues and many other sites did not fit my specific Tesla needs either. So, I hacked up A Better Routeplanner (which was a lot of fun). It works both off-car in your computer and phone as well as in the car browser. It will even follow your car as you drive and follow-up the consumption. Try it out and see if you find it useful.