You can invite a new team member to your Geotargetly account by going to to the "Team" section of your dashboard. You can decide if the new team member will have View or Edit Rights. In this section, you can also easily switch between different accounts. Geotargetly doesn't charge by user but by pageviews, so you can invite as many people as you want to your account, don't be shy!
Click on the Invite button on the top right corner:
Input the Email address of your colleague and choose what they can see.
If you have any question, feel free to contact support!