Yep, that’s exactly what it is. It’s just a standard feature that this forum software offers in conjunction with certain mobile browsers to basically create a quick access icon to the website in a special mode of the browser with few browser buttons, so more space available to see the website content.
There’s a similar option in the official app for Discourse (the forum software that BLF runs) which lets you open the site in a dedicated minimal browser:
Yep, definitely: