This plugin is useful e.g. if you want the WP Admin to know about potential problems that can be seen in the access logs.
The code is optimized to be fast and does not for example do any database lookups or use cookies.
This plugin is made by Seravo Oy, which specializes in open source support services and among others is the only company in Finland to provide WordPress Premium Hosting.
Source available at https://github.com/Seravo/wp-dashboard-log-monitor