Have a recommendation for a refresher course in a language I studied long ago?

I took four years of German in high school and college. This was decades ago. I would like to bring back some amount of my modest skill in reading and writing, even if not so much in listening and speaking. I was a straight-A student, but that was in a classroom and not the real world.

Is there a program you know of that I could enroll in online to refresh my German? A conversational course is not what I want. I remember my grammar pretty well, and I can still read some old storybooks printed in Frakturschrift, but I can’t get much out of a newspaper or magazine. And I wouldn’t trust myself to write more than the simplest message in correct and idiomatic German.

Thanks for any suggestions, especially those based on some personal knowledge or experience.