Sync between your own computers

No account, no sign-up, no email. Two machines on the same network pair with a one-time code and talk to each other directly.

1

Open Settings → Sync on both computers

On the first machine choose Pair a computer. It shows a sixteen-character code and waits for ten minutes.
2

Run the same step on the second computer

The first machine appears in the list automatically. If the network blocks broadcast, type its local address instead.
3

Type the code once

Both machines derive the same key and keep it. From then on changes travel directly between them, sealed with AES-256-GCM.

What this means

Nothing is uploaded anywhere. There is no Tomorrow server and no account to create.
The key never leaves your two machines, so nobody else can read the traffic.
Both computers need to be reachable at the same time, which usually means the same network.
To sync through a folder instead, point Tomorrow at a Dropbox, iCloud, or Nextcloud directory and let that move the files.