See:
Are you considering something like the Keybase Device registry? It would be fantastic if I could somehow add my phone number to keybase and integrate with Keybase. It would be a total hit, Keybase providing filesharing while Signal adds the messenging part, all backed up by a clever PKI that works for the online world.
Open Settings > Linked devices and tap an a device to unlink on Android. Seems there's no way to revoke (yet) in the Chrome app.
The messages are being synced automatically between chrome client <> mobile clients, which is the key feature.
[0]: https://www.whispersystems.org/blog/signal-desktop/
[1]: https://freedom.press/bundle/encryption-tools-journalists