Google testing a feature that prevents an app from downloading over a cellular network?
Previously, Google would alert users when they were about to download a large file that could eat through a user's monthly data allowance. With the new feature, Google will offer Android users a choice between waiting for a Wi-Fi hook up before downloading the app, or to have it downloaded right at that moment regardless how much data will be used to accomplish this.
Since it is being tested right now, some Android users might see this option on their screen while downloading an app. If you do get the option to choose between downloading a file now or waiting for Wi-Fi, selecting the latter will automatically start the downloading process shortly after you're connected to a Wi-Fi network, You won't have to click on anything to start the download.
Those who have tested the feature say that it is a little buggy for now. But Google will surely work hard on having the bugs fixed by the time this so called 'queue-for-WiFi downloading' is ready to be launched. And if you're the type that loves to download apps, you might find that this will save you a decent chunk of data every month.