I got a 60 day demo of Roon when I bought an Audioquest DAC . I am about half way through ...
It uses its own server technology so DNLA is out, unless your DAC, Renderer , end Point is "Roon Ready" the best you can hope for is AirPlay which drops everything to 44.1.
I depends in essence on a PC or Roon Ready Player wired direct your DAC so My Cambridge Audio CXN will not really figure. If you do this it works fine
The iPad app is a image of the desktop with its glam info , but it does not act as a streamer to "This Device" (like JRemote does) it is simply a remote to another renderer. I did use it with a Sony Vaio Tablet and the Audioquest and that worked OK
My opening impression was WOW its really a superb looking UI and simply oozing lots of info about Artists , Albums Classical Works etc, but then try and find something, it relies very heavily on the search engine to find stuff, none of the MC navigational trees etc. Also it treats each CD as an "Album" so a Beethoven Piano Sonata Set shows up as 8 Albums each with the same artwork, with no further info as to what disc is which so trying to get to a work is a bit of a mission.
When you find a track yes you get loads of related info and lots of links to other performances of that work but it is not that easy to find a track amongst my 60k tracks unless I am being dumb.
I am sure it will have loads of fans but at $120 annually or $ 500 for a life membership I doubt I will be one of them
Mike