This is an off-topic post, for my own benefit as an aide-memoire, but also anybody else who might find it useful.
Flashcards such as Anki, and many others, employ spaced repetition to learn information such as vocabulary. The basic idea is the more you get an item right, the less frequently it is reviewed. Computers are obviously well-suited to doing this, and the technology recorded here is more or less out of date. I am learning Gregg shorthand (in fits and starts, I’m afraid) and it’s a bit of a faff to get the glyphs into the virtual ecosystem. So for this purpose, I have created some hand-made cards. Archie Barnes created VOLATS for his students of Chinese at Durham. Those learning that language face a herculean labour of memorisation. Here without further ado is the handout he made to describe the system, itself salvaged and recorded for posterity by the author of the site www.earthcallingdavid.com, which has in turn vanished; but today I came across a reference to it on a Chinese learning forum, with a link to the Wayback Machine.
It’s still technically in copyright, but I don’t think Archie Barnes would mind. He is the author of the marvellous book “Chinese through Poetry” which teaches classical Chinese from scratch, without assuming a knowledge of the contemporary language, briefly described here: