You can now change default API Key to your own (in case Valve bans default one and you don't want to wait for update). Go to extension's options page to do so.
Credit goes to:
iEyepawd - original script creator
MrHayato - his script is core of this extension
Chewbacker - made logo
AquaeAtrae - functionality to check group members and management
I just packed MrHayato's script into extension and used Chewbacker's logo
Script works on pages with URIs that follow such patterns: