Expecting that you forget to logout your Gmail account from someone or public computer. Google made it easy to see devices, laptops that recently log-in to your Gmail account and also a list of IP address. Google let you see a list of recently used devices along with their locations they were associated and when they were actively using your account.
All you have to do is to navigate Sign & Security account section in your Google account setting page and head to Recently Used Devices.
Once you find unrecognized devices just simply click on it and you will see more information of it and this including the name of the device, browser name, and the approximate location the device used in.
After that head up to something looks wrong button and click on it in other to make your account secured as you can see on the image below.
Want to see the IP address who have recently accessed your Gmail account? Then to access this feature, open your Gmail account on web browser and click on the details at the bottom right corner of the page.
The page will tell you if you have appeared to be signed into your account from multiple locations at once. You’ll see the device and the IP address where the account was accessed from. In addition you can see Show details link and it show up more information about the device and application that accessed the account.
Then the last thing to do in other to ensure no one or unauthorized is signed into your account and you think someone might be. Just simply change your password this will close any open sessions and prevent people that may have your current password from signing back in and make sure the Show an alert for unusual activity in on