Good for basics... – Learn Japanese Essentials Review

'4' is actually both shi AND yon, so they are not incorrect there. Most words have 'on' and 'kun' readings- one derived from Chinese and the other from native Japanese. You won't learn much Japanese from this, but will get a structured exposure. For free, that's good.
Review by Applewhymustiputinanewnickname on Learn Japanese Essentials.