I get an always-on-top window including TeamViewer logo and link when I connect to the remote computer. How can I hide it? It seems that there's not such an option.
server spec: OS: jessie DE: mint
TeamViewer has always been designed to be unsuitable for surveillance or spying. A user should always know about active connections. For this reason, the panel can never be (completely) hidden.
However, you seem to be asking specifically about the TeamViewer Host (preview) for Linux. Unlike other versions, the panel can not be minimized yet. We plan to extend the functionality of the panel in upcoming releases.
This is still an issue in current (13) version, that panel can't be minimized. Please add this, as under Ubuntu 18.04 window is always visible in overview regardless of "prevent exit" option enabled.