Round clock · heavy bag
A jab takes a third of a second. A low kick takes a full one, and then the bag swings away for most of another. Combo Caller times every call from what the combination actually costs to throw, so nothing is called on top of you.
Free. No account, no sign-up, no network call of any kind.
The interval is the product
Every strike in the app carries the time it takes to throw and get back to guard, measured where a study exists and labelled as an estimate where none does. Add them up and the two calls below are not the same length. A timer that beeps every three seconds treats them as if they were.
1 · 2
1 · 2 · 3 · low kick
a fixed-beat timer
Punch inside a combination, 350 ms contact to contact, Piorkowski, Lees & Barton 2011, ten competition boxers at 240 Hz. Muay Thai roundhouse, 1.02 s heel-down to heel-down, Gavagan & Sayers 2017, 500 Hz. The bag's own return is an estimate and the app says so on the strike it belongs to.
01
Numbered hands, hands into legs, the Dutch four-count, elbows and knees, clinch entries, counters and feints. Every combination is in the app because a named coach or a published curriculum put it there, and every one of them has a page saying why it works, who it works against, and how to throw it.
02
Thirty programs, and every one that calls combinations is built on a named source. The rule is held by the data, not by good intentions. A program draws between five and thirteen combinations, because a wider pool brings a combination back about once a month and nothing is learned at that spacing. Build your own if none of the thirty fit.
03
A combination you have never been called is called short the first few times, then grows a strike at a time. It only ever stops on a group boundary: a feint and the strike it buys are one call or no call.
04
The screen stays on while you want it, and the coach keeps calling once it is off, through the silent switch, with the round and the clock on the lock screen. Keep your own music playing; calls duck it and it comes back. The voice is a recording, not a phone speaking: it is the developer's own, cloned, and it ships inside the app.
05
Every call is logged. Fifteen weeks of history, fourteen days of bars for each combination, a round-by-round breakdown of any past session, and a CSV of the lot.
What it will never do
There is no camera and no sensor, so the app makes no claim about your technique. It counts the calls it made, and it says exactly that. There is no account, no sign-up and no network connection of any kind: the whole thing, voice included, is on the phone. Nothing you do here leaves the device, because there is nowhere for it to go.
iPhone · English and French · free
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