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.

appally

A lightweight plugin that allows you to see active users according to their last login time/date. No need to configure, simply activate When Last and you’re ready to go! This adds a custom column to your WordPress users list of “Last Login” and a timestamp linked to that user. When Last also integrates with other plugins and now offers some more features.

User Login Plus

Show a users last login date by creating a sortable column in your WordPress users list.

Last Seen Posts Widget vs User Login Plus