What's a good app for project management?
If you have the money, you should give a try at OmniFocus. It might be a bit overwhelming in the beginning, you will need some time to adjust yourself to the application and find the most suitable configuration of the app. But as soon as you get in "autopilot mode" you will be quite satisfied.

If you are looking for some free alternatives I would recommend:


Asana
Producteev


They are not actually free, not as in beer anyway. They are freemium: you will have a set of features that are free, and another set of features that are payed, but I think that the free version do most of the job.

And there's also Trello that is simultaneously minimalistic and powerful.