I like PlugShare - mostly because you can see "check ins" and find out if people have been using the chargers you plan to recently - which could be critical!!!
The worse scenario is for you to reach a charging station that isn't working, and you haven't the range to make the next one. I recommend you plan a primary and secondary charge locations each time you set out "full" (which really means 80%). And, estimate at least a 10% reduction from your Range Indicator (GOM).