flexibility measurements · support and contact
Range measures how far a joint moves, from a photo you already took or by setting the angle by hand. It keeps your own numbers over time so you can see them change. It asks for no permissions at all, and never stores the photo.
Range is a measuring tool for tracking your own flexibility over time. It is not a medical device, it does not diagnose, treat or assess anything, and the typical ranges it shows are population averages rather than targets. If something hurts, see a physiotherapist or a doctor.
How does it measure an angle from a photo?
Three markers: one on the joint itself and one on each of the two limb segments meeting there. Range measures the angle between those two segments. When you pick a photo, Apple's on-device Vision framework proposes where the body points are so the markers usually land close to right — you then drag them until they sit where you want. The number follows the markers, so the accuracy is really down to how carefully you place them.
Do I have to use a photo?
No. Every movement can be set by hand on a blank protractor, which is useful if someone is helping you, or if you would rather not take a picture at all. The measurement is stored the same way either way.
Why does it never ask for camera or photo permission?
Because it genuinely does not need either. There is no camera code in the app. Photos are chosen through Apple's own picker, which runs outside the app and hands back only the single image you selected — the app never gets access to your library. Range declares no permission strings whatsoever, so there is no prompt to show.
What happens to the photo afterwards?
Nothing is kept. The image exists in memory while the markers are on screen and is released when you close the sheet. It is not written to disk, not added to your photo library, and not uploaded. What is saved is the number, the movement, the side and the date.
What is the "typical range" shown under my reading?
Published adult averages, shown for context only. Range deliberately does not compare your number against them — it will never tell you that you are some number of degrees short, and there is no warning colour for being outside the band. Plenty of people sit outside these figures and are perfectly fine. What is worth watching is your own number changing over time, and how your two sides compare.
Why does left against right matter?
Because your other side is the fairest reference you have. Population averages are drawn from bodies that are not yours; your own opposite limb shares your build, your history and your habits. Pro shows the gap between the two sides in degrees.
Can I get my data out?
Yes, and it is not behind the subscription. Settings will export everything as a CSV file or a plain text summary you can send to yourself or to anyone helping you. Locking your own measurements behind a payment would be a poor way to treat them.
Does it work offline?
Yes, entirely — the pose detection runs on the iPhone, not on a server. The only moment the app touches the network is when you open the subscription screen, because prices have to come from the App Store.
Range Pro runs $5.99 per month, or $34.99 per year, which is $2.92 a month if you take the year. Both include 7 days free at the start. It opens all eight movements on both sides, your full history rather than the last two readings, and the left-against-right gap in degrees. Measuring, the typical-range reference and the CSV export are free forever.
Your Apple Account is charged once you confirm, and then automatically at each renewal until you cancel. Cancellation lives in Settings › your name › Subscriptions; do it at least 24 hours ahead of the period ending to avoid the next charge. Beginning a paid period early forfeits whatever remains of the free days.
The markers land in the wrong place.
Drag them. The detection is a starting suggestion, not a decision, and it struggles with loose clothing, a busy background, or a limb partly out of frame. A plain background and the whole limb in shot make a large difference. If it keeps guessing badly for a particular movement, set that one by hand.
My readings jump around between sessions.
Usually the camera angle rather than your body. Photographing a joint from a slightly different position changes the flat shape it makes in the image, and that is what is being measured. Standing in the same spot, at the same height and distance, makes readings far more comparable — which is what matters here, since the point is the change rather than the absolute figure.
I have hit the free limit.
The free version follows two movement-and-side combinations — for example left knee and right knee. Once you have started a third, it asks you to subscribe. Existing measurements are never taken away from you, and the export stays available.
I paid but Pro is not showing.
Open the subscription screen and tap Restore purchases. That asks the App Store directly and fixes it in almost every case — most often after restoring to a new iPhone. If it does not, email below and say which Apple Account made the purchase.
Email allenjoshsamson99@gmail.com. One person answers these, usually within a couple of days. Tell me your iPhone model and iOS version and it will be a much shorter conversation.
Range measures an angle in a photograph. It does not know why the angle is what it is, and it cannot tell the difference between tight muscles, an old injury and a badly framed picture.