Admin Session Extend is a utility that allows you to extend the administrators user session. This can be helpful to admins that want to keep their sessions active while jumping between activities. This is a collection of 2 plugins that work together. The Remember me backend Provides remember me functionality. Session Extend will work as follows: If user does not opt for remember me, this plugin will set remember until browser closes. We suggest setting a short session timeout, say 5 minutes. Note: The Remember me backend plugin must also be enabled for this function to work.
DOWNLOAD: Admin Session Extend- Joomla Extension