You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature may not be available in some browsers.
No one here is clear. The only people who know work for Tesla, and they aren't answering.
But, its clear that the miles remaining is a CALCULATION not MEASUREMENT and there are a number of factors in that calculation. What's actually being measured is the voltage of the pack, but we aren't permitted to see that number. Plenty of people have shown 100% full miles varies both up and down in time, and that the max can be "reset" to a higher value (which likely really means recalculated with more recent data) So, there's enough estimations that you really shouldn't worry about it. Just drive the car.