What it teaches
Multiplication and division inside 10 × 10, asked both ways round. 7 × 6 and 42 ÷ 6 are one fact, and a child who only ever meets the multiplication half has learned half of it.
The tables are the last piece of arithmetic that has to be known rather than worked out. Everything after them — long multiplication, fractions, ratio — assumes they are there.
How it works
A fact appears; the child types the answer. No timer, and no "beat your score". The tables are the part of maths most often taught against a stopwatch, and the part that most often produces the anxiety that makes the stopwatch pointless.
Wrong answers are not marked and forgotten. They go into a five-box spaced schedule: the fact comes back tomorrow, and if it is right then, in three days, then a week, then three weeks. A child who keeps missing 7 × 8 will meet 7 × 8 rather more often than the ones they already know.
What to look for
Look at the parent screen for the facts that keep returning. There are usually only four or five of them, and they are almost always in the 6, 7 and 8 tables. Those five facts are the whole job — the other ninety-five are already known.
Saying the fact out loud together, twice, when it comes up beats ten more minutes of random practice.