For questions or bug reports, write to contact@techno-bibi.com. A reply may take a few days.
Check that notifications are allowed for the app in your device settings. Reminders arrive at 9 in the morning, a few days before an item is due. Notifications scheduled while the device was switched off are not delivered later; that is how the operating system works.
Repeat items are saved on the server. Cloud backup of one-time items, purchase history and photos is available with a paid plan while you are signed in with Apple or Google. Otherwise, these are kept only on the device.
To start sharing, you need the Couple plan or the Family plan (people who join do not pay). Create an invite code in the sharing settings on My Page and have the other person enter it. Once you approve the request, your repeat items and shopping list are shared.
See Delete your data.