If you're curious about where your Facebook account gets signed in from, or you're suspicious that someone has been logging into your account without permission, there's a lesser known feature called Facebook sessions that can tell you exactly where your account is signed in from geographically, and in most cases you can even see what device was used. Here's how to access the feature with Facebook for iPhone and iPad:
If you see anything suspicious, we'd recommend not only ending the session, but changing your password.
One thing worthy of noting is that I've experienced sign-ins from different states and locations periodically that are far away. Many Twitter users reported the same issue and even had some of the same sign-ins I did. I think this could be in relation to how Facebook handles logins on different servers but I'm not sure. If anyone else has any insight on this, let us know in the comments!