IFW

same for me too, on my FIIO M6 Poweramp would give the best UI but can't provide the same quiality sound output as UAPP or FIIO Music - both of which output at the source bitrate without resampling etc..

I'm using Poweramp on a fiio M6, no issues with the license, I just bought a website, single device, license (doesn't matter whether the email is Google or not) and entered the email and license key into Poweramp (with a network connection)