If you're not familiar with it, Samba is an open-source implementation of the SMB/CIFS networking protocol. It allows many Unix-based operating systems to connect to Windows file shares and printers, making it easy to transfer files over a network between operating systems. Out of nowhere, Google has released a Samba client for Android.

  

The app is pretty barebones, but it gets the job done. Just enter the file share you want to connect to, plus a username and password if required. Once you tap Mount, the share should instantly appear in the Downloads/Files app, allowing you to easily copy files back and forth. Opening files from the share works too - I was able to play a video file straight from my home server (granted, it was a low-resolution WMV file).

The application is also open-source, and you can find the code for it on GitHub. If you're looking for a more powerful file manager with Samba support, I recommend Solid File Explorer, but this app is great for basic operations. Google should really bake this into the Files app on Android O.

Android Samba Client
Android Samba Client
Price: Free