You book 50 minute video sessions and are paired with a random other person who wants to get work done. You start by saying what you intend to work on, and you finish by saying what you accomplished. That's it, other discussion is strongly discouraged.
I work from home and have nearly unlimited leeway over my time. This is not such a great thing, with unlimited freedom I tend to wander or do nothing. This service has helped to provide a human expectation and environment conducive to work. It's free and the days I schedule sessions are distinctly more productive than the days I do not.