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Email taron.alaverdyan.97@gmail.com. Include your device and OS version if something is broken.
Two likely reasons. Either notification permission was turned off — Settings in the app will say so and link you to the system settings to fix it. Or YET backed off on its own: if you stop opening the notifications, the app reduces how often it sends them, and after three silent days it pauses for 48 hours. That is deliberate.
Settings → "This isn't helping me". One tap, everything off, no questions asked and no retention offers. You can turn them back on in the same place.
Settings → Export weigh-ins (CSV), which opens the normal share sheet. The file has one row per weigh-in with the date, weight, change since start, and distance to goal.
Settings → Restore purchases, and make sure you are signed into the same App Store or Google Play account you bought with. If it still does not unlock, email us.
No. Your weigh-ins and photos are stored only on your device and there is no account to sync them with. Export to CSV first if you want to keep the history. Your subscription does carry over — restore purchases on the new device.
YET is deliberately blunt, but it is not for everyone and it is not medical advice. If tracking your weight is making things worse rather than better, turn it off and talk to someone qualified.