This is for file sharing, while Syncthing is for file synchronization. While you could use Syncthing for file sharing as well (and I have used it for that before), it's definitely more complicated to use, and requires a bit more setup.
Hm.. if I'm reading the README correctly this is a LAN only drop mechanism between a phone and a laptop. Syncthing does that already, albeit with a cumbersome number of features and config for that use case. If that's not accurate I'm sure you'll let me know :)
I would love to see this develop an airdrop-esque Bluetooth / PAN phone to phone feature though! Especially if a compatible iOS app were available that would be really slick.