Google released a samba client and i found it to be very useful for managing the storage of my shield remotely. It's the only app i used that has worked flawlessly when it comes to copying, moving and deleting files. I usually do all this from my PC but sometimes it's more practical to use my phone or tablet and now i can.

I suppose this can work with other android tvs, as long as you have shared storage enabled.

Play store link: https://play.google.com/store/apps/details?id=com.google.android.sambadocumentsprovider&hl=en&rdid=com.google.android.sambadocumentsprovider