I think that's just coincidental naming, the Flutter mobile framework was founded by Eric Seidel, the Flutter AR company was founded by Navneet Dalal and Mehul Nariyawala.

Interesting. I wondered why flutterapp.com (the AR/VR app) redirected to flutter.dev (the UI framework)... It led me to believe it was the same team. Apparently not. Thanks.

Yeah, flutter.io is the same. Given Google acquired the Flutter (AR) team, I assume it was just easy for them to reuse the domains when they launched Flutter (framework).