If you're not afraid of the command line, there's taskwarrior, which is pretty nice. You should definitely at least look at it. If you're an emacs user, org-mo

If you're not afraid of the command line, there's taskwarrior, which is pretty nice. You should definitely at least look at it. If you're an emacs user, org-mode with agendas is nice too. With org-mode you can "check in" and "check out" of tasks, so if you were keen assess how your estimated time to completion differed from actual time to complete, that'd be a place to start.