Friction works with every derailleur, and every speed. There are no "clicks" or indexes within the shifter. Therefore, you can mate it to any derailleur. However, you will still need a 9 speed chain for a 9 speed cassette or a 10 speed chain for a 10 speed cassette for better shifting.

I do 8 speed friction shifting on my commuter and it's awesome. Shifts butter smooth and quieter than my SRAM Force 2x10 groupo I had before. Friction shifting with 9 speed is pretty nice as well, just requires more precision. Just takes time to get used to. Currently, doing 9 speed friction on my MTB / Off road tourer.

I know people who do 1x10 drivetrains friction and love it. 10 / 11 speed friction would probably be hard IMO.