We have all been there. You are running behind to your kids baseball game, or church, or a family get together. You don't realize until you are several miles down the road that you have left your smartphone sitting on your desk at work. You don't have time to double back and grab your phone. Its not like you actually need your phone for the evening. You will be focused on the event you are headed to. Its just that now you have your entire private life sitting on your desk for anyone who walks by to look at. If you were smart you would have enabled a pin lockscreen. However most folks keep their lockscreen simple with a swipe to unlock.
To make things simple once you sign into your gmail and google accounts on your phone they pretty much stay signed in until you manually sign out of them. This means if you don't have a pin lockscreen anyone with access to your phone also has full reign over your gmail and google accounts. There is a simple and easy way to sign out of these accounts remotely.
You will need to access a PC. This may be difficult to do at the ball field, but if you can get access to a PC you will be able to log out of your accounts. In the PC browser navigate to Gmail.com and sign in. Scroll to the bottom right hand side of the page and click on "Details". A popup will show you every instance where your account is currently being used. Click the button "Sign Out All Other Sessions". Now that you are signed out anyone with access to your device will also need to know your account password to access your accounts.
via Phandroid