TLS Tunnel is a free VPN that aims to cross barriers imposed by internet providers and governments, and to guarantee privacy, freedom and anonymity to users.
The available official servers use a proprietary protocol that we call TLSVPN, it is a simple protocol that protects the connection using TLS 1.3 (and TLS 1.2 optionally), the same used in HTTPS sites, with a self-signed certificate verified at the time of connection to avoid interception.

To use it, no registration or payment is required, just a functional internet connection or knowledge to go through your provider's restrictions in case your access is blocked.