run python3 server/web.py to start the server.
The watch.py code points to Droid A & B. change the path to the desired directories and run the script.
Note:watch.py script should run at all times for sync to happen.
It can be implemented as daemon with daemon.py.
if you want to sync run python3 sync.py.
For further reading on how I implemented : https://docs.google.com/document/d/1bbwLL6f51JdvyYcBWK1alroUfCsMRaVg4Te-a-akN9Y/edit?usp=sharing