In order to share or transfer a Device, first you must set up a Contact in remote.it. Click on "Contacts" in the left-side menu, then "Create Contact":
Fill in the Contact's details in the dialog which appears. The only required field is their email address. Everything else is optional.
Available languages include English and Japanese and control the language used for notification e-mails.
Fill in the details and then click on "Create Contact".
Next you will see a new entry in the Contacts list:
Now, once your contact is a remote.it user, you can share and transfer remote.it Devices to them.
Notice that for this Contact, the Account column indicates "no". This means that the e-mail "email@example.com" could not be found as a registered remote.it user name. Until an account exists with the specified user name, sharing cannot be performed.
To invite this user to create a remote.it account, click on the "Create Account" icon:
Click on the checkbox in the dialog which appears, then click on "Submit":