There is no special button to sign out in Macrobond.
By default Macrobond can be used on one machine*. The account is locked to the first computer on which it is used. The lock can be reset if you need to move to a different machine. If you need to reset the lock, please contact Support.
You can use Clear Settings Wizard to wipe out your credentials. By default it should be located under C:\Program Files\Macrobond Financial\Macrobond
*machine is here 'one computer in a particular location'