Agile project/ticket management system

[eluser]jwindhorst[/eluser]
I've been pretty frustrated with the ticketing and/or project management systems that are available and affordable for PHP for many years. So recently I have taken it upon myself to start working on my own agile project management system that would work for me.

I'm using CodeIgniter as the framework and ion_auth as the login mechanism. I would really like to get some feedback from the community about what other systems are missing, or how the important features could be improved.