What’s the point in downloading a new version of that big 20MB application if the only thing that is different is the addition of new language support? Why bother wasting the bandwidth and eating away at the limited data plan that you’ve got?
Delta updates, which were announced back at Google I/O in June, have gone live in the Google Play Store. Android Police, who seem to be first to notice, advise that things seem to be working for previous Google Play releases.
Now, instead of pulling down a full-sized app over and over, these smart updates only add or fix the stuff that has changed since the last release. This will be a blessing to batteries, data plans, and a user’s time.
The delta update stuff has not been officially announced in a blog post as of yet however several outlets are trying to get a statement from Google.