New in Chrome 39 Beta is an improved add to homescreen experience.
Since Chrome M31, you can set up your web app to have an application shortcut icon added to a device’s homescreen, and have the app launch in full-screen “app mode” using Chrome for Android’s “Add to homescreen” menu item.
New in Chrome M39, you can define the metadata associated with your web application in a JSON-based manifest. The manifest provides a way to wrap metadata about a web application into a single file. Using this metadata in conjunction with Add to Homescreen, you can create launch experiences more comparable to native applications.
Would be very cool to see this fully supported. Could do some interesting things with AppCache while at it.