I have created a radial progress bar control, essentially replicating the functionality of the standard progress bar but displaying progress as a filling circle instead of a line segment. Very much like the circle progress bar in the Windows 10 installer.
It supports styling and automatically shapes the circle to touch the borders of the control's bounding area.
By default it looks like this (standard progress bar below for comparison)

Any interest in getting it included?
I actually find that quite useful and could think of a scenario or two where it could come quite handy! 馃槃
That was quick :)
Actually, I had already forked the UWPCommunityToolkit repo and integrated the code, so I could create a PR.
A few questions:
Got it, I'll do my best to integrate the control in the sample app and create a PR then.
And be sure to follow code and xaml guidelines stated in the contributions doc
Yeah! Really good idea!
Rather than a specialized progress ring, how about a progress control that you can specify the style you would like to have. This could be done through an enum.
example:
<controls:Progress ProgressType="Radial"/>
<controls:Progress ProgressType="ChasingDots"/>
<controls:Progress ProgressType="Bar"/>
This would make it easier for other progress styles to be added later.
in addition to what @skendrot said, it would be nice to provide custom content using ContentPresenter so you can chose what to animate
aka mother of all progress controls
Opened a pull request #828
Most helpful comment
Rather than a specialized progress ring, how about a progress control that you can specify the style you would like to have. This could be done through an enum.
example:
This would make it easier for other progress styles to be added later.