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.
I think it is now, otherwise the stream would be up an hour early (as in: you wouldn't be able to stream anything yet, not even 'Live streaming will begin soon')
I'm sure they started the stream early to avoid having thousands of people refreshing the page at exactly 3:30, which is what brought down their servers for the Model X event. If you have every watched the professionals do this, they always start the stream well ahead of time so people can trickle in. Every live stream I ever watch from Google works like this.