williewonka

This small plugin lets you monitor who logs into you site. I created this plugin because I could see that bots from china were trying to login to my site with the bettersecurity plugin but not if they were succesfull.
This small plugin saves the time and ip address from every user that succesfully logs in on wordpress and displays them on the admin dashboard. Only administrators can acces the logs.
Since version 1.2 its also possible to search within the logs.
If you have feedback on this plugin or problems with it (such as bugreports) please shoot me an email at williewonka341@gmail.com.

userlog

Allows you to see wich users have logged in when and from where.

wpsimpletools

Shows default WP / PHP log file from admin interface, gives the possibility to erase it. 
Log viewer is accessible from WP ‘Tools’ menu.

Basic Log Viewer

Does what it says

Useful plugin

Shows default WP / PHP log file from admin interface, gives the possibility to erase it. Only works if debug mode is active.

userlog vs Basic Log Viewer