With 123D Circuits.io it is possible to collaboratively work on an electronics project, much like Google Docs, but then for electronics. This is super handy if you want some feedback on your project or to invite a friend that knows how to lay out a printed circuit board.
Step 1: Open a project
The process is very simple. Open or create a new circuit design and go to the settings tab.
Step 2: Invite collaborators
Invite your friends by typing their user name (make sure they also have an account on 123D Circuit.io). They will get an e-mail with the link to the circuit and they will have access to edit it together with you.