Mirroring iPhone screen via browser
This is a little dated, and it might not be exactly what you wanted, but it still should work.  There's no simple way of doing this.  You'll need to get an app named Reflector and Google Hangouts, Skype, or iMessages to share your screen.  Here's the link to the site I found this but I'll also list out the steps in case the link goes down: http://mgalligan.com/post/29978268510/screen-share-iphone-live-on-internet    


Download Reflector (this awesome app allows your computer to become an AirPlay compatible display)
Activate Reflector - It’s simple. Just open your newly downloaded Reflector app, double-tap your iPhone’s home button, swipe left twice to show off the volume control and a small button to the right to share the screen. You should see “iPhone” or “iPad” depending on your device, and then the name of your computer below that. After tapping on the name of your computer, make sure “Mirroring” is ON. Note: You should now see your iPhone’s screen on your computer screen. Go ahead, test it out.
Start a Google Hangout, Messages.app or Skype screen share. Note: if you’re using Google Hangouts and use multiple screens, make sure that your browser window with the chat in it is on the same screen as the Reflector app. Simply choose the Reflector app as your intended screen share and voila!