About every year I get a TV box for testing. The one I got last year is this one: 'Android 9.0 TV Box A95X F2 4GB 64GB Amlogic S905X3'. It comes pre-rooted and it works with the app. It's a little less than 40 Euros. The previous year I got a 'Mecool M8S PRO Amlogic S912 3GB 32GB' it's slightly outdated but that's the one I am still using now.