Now you can share your Projects and Contexts with other users.
First you add Contacts to your account, by sending an invite that they have to accept.
The Contacts button is on the upper right corner of the screen.
Then, on every Project or Context page you have a button to share it with your contacts.

A green icon

means you are the owner of that Project/Context.
A white icon

means you are not the owner, and someone else shared his Project/Context with you.
Only the owner can Delete or Move the tasks from a shared Project/Context.
Everyone can Add tasks, Edit tasks, mark tasks as Done, or set Next Actions in a shared Project/Context.
Hope you like it.
Further suggestions are welcome.