You can make your WordPress site users to login from only single device at one time. This not only increases the security of your WordPress site but you can stop your users from sharing their login credentials with others especially if you are running a paid membership website.
WP Bouncer plugin simply works by storing a random “FAKESESSID” for each user as they log in. When a user is logged in, on each page load (init hook) the plugin checks if the FAKESESSID stored in the user’s cookies is the same as the last login stored in a transient. If not, the user is automatically logged out and shown a warning message.
Installation & Usage: Simply install and activate WP Bounce. That’s all there are no settings.