Gmail is displaying foreign countries in my “Recent activity” list that I’ve never been to.

No worries, this does not mean that another person is accessing your account.

Google is attaching IP addresses to countries dynamically so it might happen that when a lot of fellow ZenMates from e.g. Panama use our service as well, Google falsely assumes a specific ZenMate IP is located in Panama (which is not the case).

In brief: The country mapping of users in Gmail is sometimes just wrong.

If in doubt, you can easily test the physical location of IPs with our Debug Page.