I base my tutoring practice around it, and I've developed an app around it [1]. I actually encourage my students (and my app users) to use spaced repetition not just for facts, but for processes as well, like coding or mathematics. Going back to old, difficult processes and repeating them has much the same beneficial effects as doing so for facts.
One thing that Gwern doesn't mention, but that I've been very cognizant of, is how hard it is to keep up spaced repetition over a long period of time. That's a big part of why I've implemented streaks and rewards in my app, and also allowed my app users to review things on their own schedule or follow the algorithm. Just forcing users to follow the algorithm continuously tends to result in very high dropout rates.