Employee: can add expenses. Can be a supervisor/approver if he's been saved as someone's approver.
Manager: can edit company and user settings. Requires also the Employee role to function.
Accountant: sees all transactions. Requires also the Employee and Manager roles to function.
Public: Can be selected as an approver when changing a transaction-specific approval cycle.
Money checker: The final approver in any approval cycles in which the user's set as an approver.