Windows GUI for Syncthing named SyncTrayzor is also actively developed. https://github.com/GermanCoding/SyncTrayzor After SyncTtrayzor stopped being developed in 2021, it just worked along the updating SyncThing as backend. Now that Syncthing v2 came out, old one is not compatible anymore, but new one picked up the mantle.

I love this software. I am using it to sync files across different computers and different people for years now.