Google had announced this update during the recently concluded Google I/O event.
And looks like they have finally rolled out this feature.
Incremental updates mean users would get much smaller updates for the apps already installed on their Android based devices.
Instead of downloading the whole installer itself, they would only be downloading a partial one with the updated components.
The company had said that the process was automated and developers had to do nothing to accomplish this.
This is similar to how Google deliver updates for their Chrome browser on the Windows platform.