A video has sprung up showing us a build 12534 of Windows 10 for mobile. Although we don't know when or if this build will released to the public, the video gives us a glimpse of what to expect in upcoming iterations of the OS.
The video wastes no time showing off some of the new features of the build by diving into the contacts app that has new circular avatars for contact images. This is in line with what we currently find in the preview download of Windows 10 for desktop. Although brief, we also get a glimpse of the new messaging and phone dialer.
The build also features Outlook and looks identical to what we saw in late January. The video also shows the calendar integration within Outlook. Last, but not certainly not least, we get a look at 'Project Spartan' for mobile which was just released for the desktop version of Windows 10.
Currently, Windows 10 for mobile is limited to a few handsets via the 'Windows Insiders' program, but that should change with a plethora of other devices expected to receive the update in the near future.