Do you want to check the balance of your wallet without having your Trezor connected to a computer or a phone? You can generate a so-called ‘Watch-only wallet’ that allows you to review your accounts without connecting your physical Trezor.
Trezor Suite application can serve as a Watch-only wallet as well. All you have to do for Trezor Suite to turn into a Watch-only wallet is to first click on the name of your device in the top-left corner of the app:
And then toggle the ‘Remember’ button:
This way, your accounts will be saved in the app, and you can always review them just by opening Trezor Suite without the need to connect the physical Trezor to it.
The Watch-only wallet, as the name says, allows you only to review your wallet; you cannot make any transactions. The transactions must be signed with private keys stored in your Trezor. Therefore, to make a transaction, you always need your Trezor connected.
If you wish to use a third-party app to generate a Watch-only wallet, you must go to Trezor Suite, where you can get the Account public key (XPUB).
Here is how to display XPUB in Trezor Suite: https://trezor.io/learn/a/trezor-suite-app-public-keys-xpub
Then you can import it to any third-party app of your preference that supports XPUBs.