Microsoft announces Windows 10 Build 15031 today for developers who are part of the Windows Insider Program.

It adds a feature called Compact Overlay which is essentially an always-on-top window aimed for video players and chat applications. Skype and the Movies & TV app will support Compact Overly and show a small window that sits on top of other applications so users can keep watching videos or video-chatting while browsing the web or typing a document.

This new build of Windows 10 also supports automatic unlocking when the user is nearby. This is achieved by pairing the Windows 10 PC with the user’s phone via Bluetooth. It also opens the possibility of using smartwatches as the unlocking device. The feature is referred to as Dynamic Lock.

Aside from these two features, the Windows 10 Build 15031 Preview for developers has a new share icon, more games that support the Game Bar and tons of fixes for issues of the current build of Windows 10.

Since this is a preview build, only developers are advised to download this for fixing bugs and testing. If you still want to check it out, go to your Windows 10 PC’s Settings > Update & Security > Windows Insider Program.

A Windows 10 Creator’s Update is slated for release ‘early this year’ which promises a lot of improvements to the operating system including a 3D support for Paint and Microsoft Office applications as well as a focus on virtual reality.