Tailscale

Website
F-Droid Link
Open Source (BSD 3-Clause "New" or "Revised" License- so... you know.) networking service. Skyrocketing commercialization of the product through recent, massive ($160M) series funding. Some concerns with scaling, but the company and its technology seem promisingly positive for ease-of-use and interfacing.

Tailscale is WireGuard made easy. So, it's a convenient Privacy Tool that's relatively beginner-friendly.

Tailscale lets me access my devices from anywhere - mobile devices (installable from F-Droid), desktop computers, self-hosted servers, and travel routers can all connect to each other securely.

There is a stupid limitation with devices not being able to be connected to two VPNs at a time, but Tailscale partnered with Mullvad VPN to offer a plugin through the Tailscale admin console but it's not perfect for mobile.

Tailscale on mobile kinda sucks for convenience because of that, since someone should always have a VPN running anyway.