Not talking about FiiO Music - obviously that's going to bypass stock Android and natively play high-res music. Are you aware of SRC and what it means in the Android world?
In case you're not - or anyone else isn't - Android apps typically have to output audio through the Android audio stack, which uses SRC (Sample Rate Conversion) to resample/downsample all audio to 16/44.1 to standardise audio output for the huge number of Android devices out there. That means that playing back a high-res Flac file (24/96 for example) in a typical music app on Android only gets you 16/44.1 audio from your headphones, and potentially alters the quality of the original file as well because it goes through a resampling stage. That's why dap makers like HiBy make such a big song and dance about their audio bypass tech (in HiBy's case called Direct Transport Audio, or DTA), because ANY app you use on their daps are output in the correct bitrate, and not subject to SRC. This is exactly what
@WianFiiO just casually claimed the M11 does as well, which is HUGE, because for the best part of a month myself and many other members on this forum have fished around for apps (like UAPP) that can bypass SRC and output true high-res audio from the M11 (in the case of UAPP and the likes of Neutron, using their own device-specific drivers). If the M11 natively bypasses SRC for every app, it means you don't need UAPP et al to enjoy high-res music; in fact Tidal MQA and high-res streaming via Plex is output as high-res.
Sure UAPP, Neutron and other music apps are better at playlists and rendering special characters and arranging songs and albums by Album Artists etc. etc. I use Poweramp for the same reasons. But those aren't the main reason people were seeking out those other apps - they wanted SRC bypass, and it turns out we've had this all along...