Lets a student mark they've finished an activity. The student can click through two states of the XBlock, shown below:
FutureLearn uses this kind of thing to great effect. Students can read text, watch videos, etc., and indicate when their done. This is convenient both for progress indication to the student (know what they've done, and for honor code grading (indicating to us that they believe they've finished an activity).
I copied some of the UX patterns from FutureLearn so that users of both platforms would have consistency of user experience between MOOCs. I didn't copy them exactly since I wanted to be unambiguously in the clear with IP issues around look-and-feel, and this was on a short anough timeline that I did not have a chance to reach out to FutureLearn for permission. As a footnote, this kind of collaboration between MOOC providers is probably worth pursuing -- it'd be to the benefit of learners on all platforms, and ultimately, the industry as a whole if we had consistency of experience between platforms where convenient.
This now includes some styling and wording tweaks from Stanford.