Click "Sign out" on the bottom of the menu ... out of your Gmail app or any other Google apps, just from your Google account in a mobile browser. And here's how to do it: 1.
To sign out of your user account, press the Windows key, click your account name ... This can cause those apps to misbehave the next time you launch them. If you use cloud sync apps like Google Drive ...
Once done, you will be signed out of your Google account on all devices at once. However, this method has some limitations. For example: It doesn’t sign out of your Google account on the device ...