To add new users to your Silktide account, you must be an account owner. There is no limit to the number of users you can add to your account.
Click on the icon in the bottom-left corner, and select Account settings.
In the menu that appears, select Users. Click Invite users and a dialog will appear:
Here you can enter the details for one or more users at once. The drop-down menu on the right of each user specifies what role they have.
When you fill in this form, Silktide will send each user an email with instructions on how to create their own account. You can optionally check the Include welcome message box to include your own custom message in that invitation email.