No need to be sarcrastic. He is absolutely right. The seed is all you need in case of the common TOTP algorithm. There is no connection to the device.
In fact, in Google Authenticator you can even conveniently export all running TOTP to another Google Authenticator without any connection with the apps or anything else whatsoever.
(And yes in theory you could remember the hash, and have a custom TOTP client that lets you enter it in. But unless you do this it is a theoretical argument only).
