add to home screen
Add to home screen is a common mobile browser UI feature that allows a user to add a bookmark to the current page, to their mobile phone home screen.
This feature was introduced in iOS, likely as part of the initial release as *the* way to "install" new web apps from Safari onto your iPhone, since there was no iOS native app (public) API, nor iOS App Store.
Choosing "Add to Home Screen" (from inside the "share" button box with arrow sticking up out of it, brings up a "Add to Home" dialog:
When you tap "Add", the icon shown (e.g. the Pownce icon in that example), is added to an empty spot on your home screen with the given text. Tapping it opens the web page in Safari, or its own process if the page had a special meta tag ("mobile-web-app-capable" for iOS and/or "apple-mobile-web-app-capable" for Android, both with content="yes").