I put the Projectivy home screen on my various Android/Google TV devices, which is clean and ad-free.

A couple of older devices it "just works" on. A newer TV with Android built in requires minor adb commands to disable the return of the default home screen, but it's been working for ~6 months, including a TV software update (which my wife initiated and I was worried might turn things to their default status, but didn't).

Apple TV will be my next device if the above becomes locked out.