MyBB Community Forums

Hello. How can I add a thread prefix system like the one here in the MyBB forums? Like the [How To?], [General] etc...? Also, how can I display how many users are browsing the forum? (Example : Forum Annoncements (2 users browsing)

ACP >> Configuration >> Thread Prefixes

ACP >> Configuration >> Settings >> Forum Home Options >> Show x viewing forum

Thank you!