Facebook WiFi alternative
With Facebook WiFi shutting down on June 12, 2023, You can use Spotipo as an alternative.
Understanding UniFi Captive Portal: What Happens Inside
Understand how does a UniFi captive portal works and how to debug issues
What is an UniFi External Portal Server?
An external portal server allows deploying Guest WiFi networks that are more advanced than what’s builtin into the UniFi controller. Examples include collecting email addresses, selling multi-device access, etc.