Normally, when an app gets an update, you have to re-download the whole app from the Play Store to get the latest version. This isn’t a big deal if you’re just updating a small 2MB app, but when the app is huge, it’s annoying.
To speed things along, Google announced Smart Updates at Google I/O last June, which reduces what you need to download to just the updated portion, or the delta. We’ve been waiting for this since the announcement, and today it looks like Google enabled the feature in the Play Store.
Smart Updates seem to have been implemented on the server side, meaning you don’t need to have the latest 3.8.15 version of the Play Store installed to reap the benefits. The folks over at Android Police ran some tests and noticed that today’s Instagram update, for example, only needed to install 3MB out of the total 13MB. That’s a 10MB savings. Not bad!
Hit the source link to check out videos of some other smart app update examples.
source: android police