Change your role to 'Approver' via the drop down arrow top right of your screen:
You will immediately arrive in the Approver's Dashboard with an overview of users you are approver of if they have uploaded
- Expenses for approval
- Unsubmitted expenses
By clicking on a users' line in the first section - Expenses for approval - you will be able to see all of the expense you can approve or reject and you can open each expense line for more details.
By clicking on a users' line in the second section - Unsubmitted expenses - you can send a reminder to users so they do not forget to submit their expenses and you can approver or reject them.