Roon App on Apple iPhone

I have been using VOX and like the idea of dragging the FLAC files onto the VOX Apple Mac Media Player. It then syncs with the VOX cloud, formerly LOOP service. I can download FLAC Albums to the iPhone. How can I replicate this and or play my FLAC Albums on my iPhone?

I use hfplayer by Onkyo on my iPhone for flac and even dsd playback.

while I don’t have an iPhone, I currently use CloudPlayer on my Pixel 2 XL. I’m syncing my collection to Google Drive (though it supports OneDrive and Dropbox) and can access, stream or sync content on the fly which is great. I’d obviously love to have Roon instead, but that seems to remain on the horizon for now.