Ask HN: Project Management app for freelancer?

My work recently changed from working on a project-to-project basis to working on multiple projects at the same time. It's starting to get time consuming to keep track of all the feature requests, custom quotes and actual work performed, so that I was wondering if the HN users could recommend any project management software?

I am basically looking for something that takes care of the administrative tasks related to the projects, such as quote-, job requests-, jobs performed- and contact tracking. Team management is not needed at this time and it also doesn't require any repository integration or bug tracking.

Any recommendations?