One other thing I want to add is that if you have a YouTube video content that’s worth some setup time to get the desired audio experience from the APP2, there are ways to download it into a video file so you can play on VLC and listen via the iphone VLC Streamer.
What I’ve been able to try out successfully is the YouTube-dl script. You download the .exe version of it and run it in the command prompt with the shared URL that you copy from the YouTube video of interest. It’ll write into an .mp4 file for you. You can also add options to also download the subtitle if one’s available, or an auto-generated subtitle as well. But I tried it out with an video with auto-generated subtitle and the options for subtitle in youtube-dl didn’t work for me. I ended up using an online free service called downsub.com (you just put in the link and it generates an .srt file online for you) and that works better.
Of course all of that takes a little bit of extra time to set up, and the run time will be as long as the video because you’re capturing the stream into a video file. But it all runs in the background anyway while you do something else. When it’s done, you just load it into the Windows VLC Streamer Help for processing like with any other videos so you can get the APP2 audio experience from the iPhone.