You can manage the users who have access to your Alooma system via Settings / User Management.
Add a new user by clicking Invite User at the bottom of the page and providing their email address. The user will be sent an invitation by mail which they will need to accept and provide an Alooma password.
Until a user has accepted your invitation, their name appears in the Pending Users list. From there you can either resend them the invitation mail, or remove them.
Once a user has accepted your invitation, their name will appear in the Users list. You can remove a user by clicking Remove.
Note that all users have equivalent access permissions to Alooma, so any user can add or remove other users, as well as access and modify all parts of the Alooma platform.