What it teaches
Eighty flags and the countries they belong to. Flags are the easiest way into world geography because they are already everywhere a child looks — on shirts, on number plates, at the start of a football match.
The capital city is shown once the answer is right, so a second fact arrives attached to the first rather than as a separate thing to learn.
What to look for
The confusable pairs are the interesting part: the Netherlands and Luxembourg, Ireland and Italy, Poland and Indonesia — the last two being the same two colours the other way up. Those are worth a sentence out loud when they appear.
Find the flag asks the same thing backwards, which is harder.