There looks to be a new update out on Windows Phone 8.1 for those in the Preview for Developers program



From Windows Central:

This new build is notable for enabling a 'real-time Live tile' for the Battery Saver app on Windows Phone 8.1. It also allows you to add Battery Saver to the Quick Settings found in the Action and Notification Center.

To check your phone right now for an update go to settings -> phone update -> check for updates. If you're enrolled in the Preview for Developers program, you should see an update. Look for the 8.10.14203.306 update to be available after checking.

  New Windows Phone 8.1.1 build 14203 available to download