All of your leads have their own country flags in Teamgate, so that you may easily recognize where they're from. You can add the flag by following these steps:
Click on the lead you want to edit, and you'll be transferred to the lead's card.
Click the "Edit" button.
Select your lead's country in the address section.
Save your correction.
After these steps are completed, the flag will be changed automatically and you'll see it in the Leads list and the lead card too.