If you would like to share the iota with other iota tracker user accounts, you can do so from the settings menu. To get to your iota tracker settings menu, navigate to the map screen for that iota, press the ellipsis (...) button in the bottom right corner to extend the footer, and select 'settings'. Select 'Invite to share' from the settings page and select the person you would like to share with from your contacts list. Your contact will now be able to view locations and see alerts, however that individual will not be able to edit the settings for that device.
Multiple individuals can also access an iota tracker's information by logging into the same account from multiple smartphones/tablets, which will give all users editing privileges.