Janis Elsts

Normally when you login to your blog WordPress will create a session cookie that is used to authenticate you. If someone was to steal the cookie they would be able to use it to get full access to your blog without having to know your password. This plugin prevents that from happening – it makes the cookie specific to your IP address, so it won’t be usable from a different computer.
Use this plugin if you have a static IP. If you have a dynamic IP address and it changes often you will get logged out frequently.
A bit more info can be obtained from the <a href="http://w-shadow.com/blog/2008/07/12/safer-cookies-plugin-for-wordpress/" title="Safer Cookies homepage" rel="nofollow ugc">Safer Cookies homepage</a>

Safer Cookies

Ties the WP session cookie to your IP address so that it can't be used to get access to you blog from another computer.

Nomad Programmer

It will help you to make only one logged in at a time on WordPress sites. if user wants to log in two or other places than it will destroy all other sessions.
This Plugin uses function like WordPress 4.1, that have a button on the user profile screen which clears all other sessions, and on the user editing screen which clears all sessions. This plug-in can limit simultaneous login. This plugin use for every user automatically.
<h3>Licence</h3>
<a href="https://wordpress.org/about/gpl/" rel="ugc">GNU General Public License</a>

One Active session

Working till now

This plugin clears all other logged in sessions and allow only one login by one user

Safer Cookies vs One Active session