Why can't I find add to home screen?
If you do not see the "Add to Home Screen" option after you have opened the Mobile Gallery App installation link, you are most likely viewing from an unsupported browser (i.e. using the Gmail app on an iOS device, or the Twitter app from an Android device).
How do I add a website to my home screen?
Open Chrome. Navigate to the website or web page you want to pin to your home screen. Tap the menu icon (3 dots in upper right-hand corner) and tap Add to homescreen. Choose a name for the website shortcut, then Chrome will add it to your home screen.