On rare occasion, you may launch Due to find your data missing and replaced with the walkthrough reminders and default timers.
Due automatically keeps a local backup of your database every time you return to the Home Screen from Due app.
You can restore from any of these backups in Due > ☰ [Side Menu] > Backup. Tap on the latest backup and choose 'Restore'.
It is important that you do not delete Due from your device. All local backups will be deleted once you remove Due from your device.
If you do not see any backup, you should restore your device from your last iCloud/iTunes backup as soon as you can (before the next backup overwrites the existing backup).
Finally, even if you do not require sync across devices, consider setting up Dropbox sync in Due > ☰ [Side Menu] > Sync. This can serve as a handy remote backup.