Opensource PHP Timesheet required

Hi people, We are looking for a implementing & maintaining an open source timesheet application in PHP. We already have a small intranet site developed in PHP Codeigniter framework so we would like to know if there is any PHP timesheet application developed in codeigniter framework. We got to know that there all many PHP based timesheet application, but the issue now is we need a single username password for both the existing intranet site and the new timesheet to be developed. So before accepting the bids we would like to know which PHP timesheet application you are going to suggest us based on our requirement. This project is for implementing, if possible integrating the timesheet with the existing intranet portal and maintaining it for the first 3 months. Thanks in advance