Kids Math Online

Kids Math Online is listed here under Puzzle. There is no launcher and no install between you and it. It is built for touch, so a phone or a tablet is the natural place for it. Its tags here are educational, endless, html, html5, hypercasual.

It is drawn for a tall screen, so it fills a phone held upright rather than a wide monitor. No account, no download, no wait — the game is the page.