I really like Archos for fetching data and creating a media library from my external hard drive (the UI looks just like a google one).
But it's currently broken on The Shield. (Doesn't allow media to be added from harddrive to library)
What's the best alternative? (Not a player, but an app that creates a library via Hard drive)
I think Mizuu is what you're looking for but navigation will probably be a bit wonky (may need a mouse), I think you'd have to sideload it as I'm not sure if it's avaliable on the Android TV play store. The version I have has a leanback icon and can use the global search so that's a big bonus.
Although development for Mizuu stopped a while ago the latest version works with Android TV and the dev is working on something new that should hopefully replace it.
Kodi is the other option, the UI isn't material at all but it can look pretty spectacular with the right theme. Kodi can very much act as a homescreen for Android TV with configurable shortcuts and addons that make a complete media experience.
Seems a bit like https://github.com/Fleker/Amphitheatre
Of course, the app was never published.
From an external drive you mean? I use Archos and my media is on my NAS. It's perfect.
Archos works with external drives. Check your permissions.
SPMC with Metropolis skin is a great alternative. I was in the same boat as you but now prefer SPMC. The skin can be downloaded within the app in settings.