How to use it

Pick a size. 5×5 is the classic; 3×3 is a gentle start, 7×7 is a real hunt.
Find and tap the numbers in order, starting from 1. The clock starts on your first correct tap.
Try to keep your eyes near the centre and let the numbers come to you, rather than reading row by row.
Compare against your own best for that size; it's saved on this device only.

Why it works

Honest answer: a Schulte table is a visual search game. You'll get faster at it with practice, but that doesn't mean your attention in general has improved. Reviews of "brain training" find that people improve on the trained task, much less on closely related tasks, and there's very little evidence for gains in everyday attention (Simons et al., 2016). We found no peer-reviewed study of Schulte tables themselves.

So use it as what it is: a one-minute warm-up for your eyes and hands, and a quick way to notice when you're too tired to focus.

When to use it

As a short warm-up while a match loads.
Late at night: if your usual time suddenly feels like a slog, that's information.
As a calm, screen-light break from the game you were playing.

Not medical advice. This is a wellbeing tool, not a treatment. If things feel heavy, talk to someone.