After years of searching for a good Software Project manager, and trying a lot (the free ones mostly but some unfortunately bought) I finally reached Pivotal Tracker and got immediately interested by its first sight simplicity hiding a very powerful PM that suited perfectly our needs.
I am not a dogmatic Agile programming fan but some of its concepts seduced me, I got interested in GTD methogology , but I found it too personal to be suitable for a team and I was looking for something like a mix of both.
Tracker is flexible enough to let you use it from a simple todo list to a big agile project without ever upsetting you with the usual Error: required field empty (except when you don't enter the story name, but I can live with that). The account setup was immediate, the help page very clear, and they have an API based on REST that accesses directly the database and allows you to virtually do anything.
I got so sure of my choice that we immediately started to develop a couple of tools:
For #1 as we are mostly based on Mac OSX, we developed a very simple Dashboard widget that can be downloaded
We are currently working on the migration script that I will upload here when it will be ready, in a couple of days.