On computer and laptop you use either the windows, linux or mac version, on smartphone and tablet the android app (which is basically an additional GUI on top).
Once all devices "know" each other (you add their IDs in the other syncthing instances), you can add folders to be synchronized between all or a selection of them.
http://imgur.com/vvVlRXL
I am not sure about how well syncthing is yet supported on a windows 8 tablet, but one could just try it out or ask in the syncthing forum.