Not-so-Simple TODO script with Cron job

Small PHP web script to allow multiple developers on a project maintain a communal TODO list to help development, with useful features and email notifications. * Flatfile database (two files) * Add, Complete, Remove, Edit options * Coloured categories * Due dates, visual overdue notification * Attribution of todo items to different people * Email notification via cron with reminder date and frequency option * Basic file locking mechanism to make sure one developer updates at a time (avoids confusion) * Easy to integrate into site template/design * Security available through directory protection (.htaccess) not included. * Simplified GUI at click of button, or setting