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.
If you turn on the climate control via the Tesla app, aka preconditioning when the Tesla is not plugged in, if the battery state of charge drops to 20% or less, then the climate control will turn off sooner than 4 hours.