Windows Phone 8.1 has only been out for a few weeks and, still in beta, the software is only available to developers. Still, Microsoft is furiously attempting to ready the update for a public release later this month, and has issued its first update this week.
Build 8.10.12382.878 does not include new features, but improves overall performance and battery life, while making it easier for some apps to stay open without crashing. The earlier build, coupled with the fact that many developers hadn’t updated their Windows Phone 8 apps to support the new version, was unstable.
In our initial tests on the Nokia Lumia 1020, we’ve noticed substantial improvements in battery life, though it remains to be seen if the recovery is such that it will bring it back to Windows Phone 8 levels.