It tells youwhat to fix.
Point your phone at yourself. Therox follows your joints through the set, counts your reps, and calls out the fix while you are still lifting: raise your hands, straighten your back, slow the drive.
- Coverage
- squats, hinges, presses, overhead work, pulls, rows, arms and shoulders
- Your footage
- Never leaves your phone
Live form check, unedited. A clean set, counted.
Three steps, no tapping mid-set
- 01
Set the phone down
Each movement tells you whether it needs a side view or a front view. Get your whole body in frame and start the check.
- 02
Do your set
Nothing to tap mid-rep. It follows your joints while you lift and calls out what it sees as you go.
- 03
Get the rep and the cue
Most reps count, and you hear the fix while you lift: raise your hands, straighten your back, slow the drive. The count is held back when a rep is a long way off, or when you are doing a different movement from the one you picked.
When a rep counts
Most of them do. If your form drifts a little you still get the rep, and you hear the cue that goes with it: go deeper, straighten your back, slow the drive. The count is held back when a rep is a long way off, or when the movement is not the one you chose.
That is deliberate. The limits it uses to judge a rep are sensible starting points based on how bodies move, and a check that fires on every decent rep is more annoying than useful. So for now the cues do most of the work and the counting stays generous.
As we test those limits against real footage, the bar tightens.
Think of it as a second pair of eyes: it helps you catch things in the moment, and it works best alongside learning the lift properly.
What it checks, and where it stops
25 movements across 8 families, each with its own checks and its own camera angle.
- Squat patterns
- Hip hinges
- Horizontal press
- Overhead press
- Vertical pull
- Rows
- Arms
- Shoulders
There is a full reference for the detail: which camera angle each movement needs, what each cue measures, and why calf raises and shrugs are not included.
Read what it detects, and what it doesn'tYour footage never leaves your phone
Pose estimation runs on your phone's own processor. No frames are uploaded, none are stored, and none are sent to a third party. What syncs to your account is the results: rep counts, form scores, check results.
There is no ad network in the app, and nothing from your camera is sold or shared. The privacy policy spells out exactly what is stored.
Common questions
- Can an app check my squat form?
- Yes. Prop your phone up and Therox watches you through the set, then tells you what to fix while you are still lifting: go deeper, keep your back flat. It coaches squats, front squats, goblet squats, lunges and Bulgarian split squats, filmed from the side. Think of it as a second pair of eyes in the gym, there to help you catch things in the moment. It works best alongside learning the lift properly, not instead of it.
- Can a phone camera count reps?
- Yes. Going down and coming back up is a big, clear movement, and a camera picks it up easily. Therox counts as you go, so there is nothing to tap between reps or sets. A slightly messy rep still counts and you will hear the cue that goes with it. If a rep is a long way off, or you are doing a different exercise from the one you picked, it holds the count back.
- Do I need a wearable or a smartwatch?
- No, just your phone and somewhere to lean it. There is no watch, chest strap or extra kit to buy. Because Therox works from the camera rather than a sensor on your wrist, it can see the shape of a movement rather than only its rhythm, which is how it can tell you whether you reached depth.
- Which exercises can it check?
- 25 movements across 8 families: squats, hinges, presses, overhead work, pulls, rows, arms and shoulders. Each one has its own checks, like depth, lockout, back angle and bar path, and each works best from a particular camera angle, which the app tells you before you start. Two you might expect are missing: calf raises and shrugs. Therox follows your ankles rather than your heels and toes, and a shrug is a small enough movement to be hard to read reliably, so we left both out rather than guess.
- Can it check planks or yoga poses?
- Not yet. Therox gives its feedback at the end of each rep, and a hold never finishes one, so it stays quiet through a plank or a held pose. Hold support is something we want to add, and a good part of the groundwork is already there, since it watches your body line on push-ups. Until then it is honest to say Therox is a rep counter that checks form, and a plank is not a rep.
- Does my workout video get uploaded?
- No. The camera work happens on your phone, so no frames are uploaded, kept on a server, or shared with anyone. What syncs to your Therox account is the outcome rather than the footage: your rep counts, your scores, which checks passed and which exercise you did, along with the name and email on your account. The privacy policy has the full detail.
- How accurate is it?
- Good, with the occasional miss. It counts clean sets reliably and picks up real mistakes, and like anything working from a camera it gets some wrong. We have not put a percentage on it, because the limits it uses to judge a rep are sensible starting points based on how bodies move, rather than figures measured against recorded sets. Those limits get tighter as we test them against real footage, and there will be a number worth quoting once they have been.
Put it to work
Early access opens when the app does. We will email you then, and for nothing else.