In a late-night backend update, Google turned on Delta Updates in the Play Store, a small but exciting feature announced during Google I/O. The idea is simple: instead of re-downloading the entire .APK file when an app is updated (as has been the case until now), users will only download the delta, or differential, between the old and new app. So your 13MB file, for example, will not be only a few kilobytes, or if there’s a big change, a few megabytes.
To me and you this is not the biggest deal — what’s a couple MB here or there – but to Google, who lays out terabytes of bandwidth per day to hundreds of millions of Android users, it is going to save a lot of money. For data-limited Canadians every bit and byte counts, so we’re happy to see this feature enabled.
Via: Android Police