A benchmark for visual memory and reaction.

Six tests. One number each. Free, on iOS.

Coming to the App Store

What it measures

Visual memory: How many positions you can hold at once, from a single flash.
Overdrive: The same task against the clock — ten levels, ranked by how fast you clear them.
Reaction time: Simple reaction speed. Median of five measurements, false starts caught.
Precision: How close your recall lands when there is no grid to snap to. Error is a distance.
Filter: Whether you can stop a hand that has already started moving.
Scan: Memory on top of deciding what is relevant in the first place.

Daily Challenge

One board a day, identical for every player. The first attempt is the one that counts; the rest are practice. The grid you share afterwards shows the path you took, not just the total.

How results are checked

Every run that enters a leaderboard is replayed on the server using the same code your phone ran. A result that cannot be reproduced does not get in. Themes change colour and never difficulty — a test enforces it.

Gridbench measures performance on visual and motor tasks. It is not a medical device and not a diagnostic tool. It does not train your brain, improve your memory, or tell you anything about your health.