Open Weighline first, then step on the scale. The app listens only while its weighing screen is open.
Check that your scale is supported: today the Xiaomi Mi Smart Scale (Mi Smart Scale 2) and the Xiaomi Mi Body Composition Scale 2. Scales that use other apps, for example OKOK, are not read yet.
Bluetooth must be on and allowed for Weighline: Settings → Privacy & Security → Bluetooth → Weighline. If it is off or not allowed, the app shows one line and a button to Settings.
Stand still until the number on the scale stops changing. The scale sends the final weight only then.
Some scales go to sleep after a while; step off and on again to wake them.
“Is this your scale?”
The first weighing from a scale Weighline has not seen asks once, because a neighbour's scale may be in range. Tap "Yes, remember it" and later weighings from it save by themselves; other scales are ignored. Bought a new scale? Settings → Forget this scale, then weigh once and confirm.
The weight did not save
Weighline saves a weighing only when the scale says the weight has settled. Weights outside 2–300 kg are never saved. If you step off before the number settles, nothing is saved; just weigh again. In the demo nothing is saved at all.
Apple Health
Turn on Apple Health in Weighline's settings and allow Weight (and Body Mass Index) in the sheet iOS shows.
If you said no in that sheet, change it in the Health app → your profile → Apps → Weighline, or Settings → Health → Data Access & Devices.
BMI goes to Health only if you set your height in Weighline.
A weighing is always saved in Weighline first; if Health refuses it, the weighing is still kept and History shows it is not in Apple Health.
Apple Health sync is free.
Units and BMI
Choose kg, lb or stone in Settings; the scale's own unit does not matter. BMI is your weight divided by your height squared; it is a rough guide, not a medical assessment. Weighline does not calculate body fat.
I see only 30 days of history
The free version shows the last 30 days. Older weighings are kept on your iPhone, and Weighline Pro shows them all with the 90-day and all-time chart.
Restore Weighline Pro
Settings → Restore Purchases, signed in with the same Apple Account. Refunds are requested from Apple at reportaproblem.apple.com.
Privacy
See the privacy policy. Weighline has no account and no server; your weighings stay on your iPhone, and in Apple Health if you choose.