First, we've added detached accounts. Now you can start assigning tasks to someone without inviting him or her by email beforehand. Just use Add a person button in People tab to add a detached account. Of course a real user can be invited to take over this account later.

Second, we must say that our users really love task groups. This why groups were greatly improved! Now opened group appears above main canvas in a window. Yeah, it is possible to drag and drop tasks inside and outside!

Our team will be happy to receive a feedback from you about our product.

Stay tuned!