Got a couple of minutes?
 
Here’s a quick tip on how to check every device (mobile phone, browser, etc) where you logged in to your Facebook account.
 
Open your Facebook account, go to Settings, click on the Security tab (it’s the second one) and review these two fields:
 
Your Browsers and Apps – From here you can check all the web browsers and apps you saved in order to access your Facebook account without (re)confirming your identity. Don’t recognize one of them or you don’t use them anymore? Disconnect them immediately. Keeping them active only makes you vulnerable.

Where You’re Logged In – Use it together with the previous feature to review your logged-in status. End activity for any device or place that doesn’t look familiar. Also make sure you remove any devices that you don’t use anymore, such as the ones used in former workplaces or ex mobile phones.
 
Here are more tips on how to secure your Facebook account.