Where is my data stored in the free version?
In the browser of this device. In the future Android app, data will also be stored on the device. It is not sent to our servers, except the comments and answers you choose to send.
Does it sync between devices?
Not in the free version: each device has its own data. In Plus, yes: data is stored online and syncs between devices.
How do I make a backup?
In Settings & plan, in the "Backup" card, download a copy. To restore it, use the same card.
What happens if I clear my browser data?
The data of the free version is lost. Make backups regularly.