Ultraflix mentioned https://www.cnet.com/produc
Post# of 96879
https://www.cnet.com/products/samsung-qn65q7f/review/
The UltraFlix app has some niche 4K content and there's 4K support on the YouTube app. Other major apps like Hulu, Plex and both HBOs (Go and Now) are on-board too, but if you want more you'll probably still need to connect an external device like a Roku or Apple TV.