A countdown for the board, big enough to read from the back row. One tap for the usual lengths, or set your own. No sign-up, nothing stored.
05:00
Put this page on the classroom screen, pick a length and press start. The bar drains alongside the numbers, so a pupil who cannot read the digits from the back still knows how much is left. At zero the whole panel turns red and, if you left the sound on, it beeps once.
The usual lengths are one tap because those are the ones a lesson actually uses: a minute to tidy up, three for a think-pair-share, five for a task, ten for group work. Anything else goes in the box, up to 180 minutes.
Learnify turns the class into a role-playing game run from the teacher's screen: points for real reasons, avatars that evolve, attendance, groups and quiz games. Pupils need no devices and no accounts of their own.