Bugsense-kohana is a project mainly written in PHP, it's free.
Kohana 2.x module for bugsense.com
Bugsense
Exception tracking using bugsense.com (for KohanaPHP 2.x)
Clone into yout modules directory (as bugsense) and then enable the module in your application/config/config.php Then copy config/bugsense.php and specify your api.key