If you’ve ever sold off a used android phone then you have probably forgotten to unlink the GMAIL account from that phone, while this might not be a problem if you have used a dummy account, it will be a problem if its your personal account, because the person you sold the phone to has access to your emails, linked phone numbers, applications and alot of valuable and private information of yours, but google has made it easy to check what phones/laptops your email has been linked too and sign off remotely from them.
Firstly you need to go to this website, if you are signed in this will work instantly, but if not you will have to sign in to your email using gmail or another service, once you’re signed in you can see all of the devices linked to it, if you see anything suspicious you can click on it and see more information about the device model, the browser used and the last time and place it was linked to your account.
If you want to remove access then you can click on the little red button with “REMOVE” and google will ask you if you want to remove access, click remove and it will be removed, you can also click on android device manager if you want to delete all information from this phone. And you can change your password in case someone has hold of your account using “secure your account”.
