ruudkok

Don’t keep logging in to your WordPress admin panel over and over again. Install this plugin to remain logged in to your blog for up to a year (unless you log out manually).

WP Keep Me Logged In

This plugin will increase the session time of your WordPress login cookie to 1 year. That way you won't have to login over and over again.

curlybracket

This plugin creates a widget which will show the title, thumbnail and link to the last 5 posts a user has consulted. 
To store the data it uses sessions.
Session handling is provided by slightly modified functions from the simple-session-plugin by pkwooster.

Last Seen Posts Widget

Show title and links to the last 5 posts a user has consulted.

WP Keep Me Logged In vs Last Seen Posts Widget