I am looking at a todo / project / task management application for Linux that goes beyond making a simple list of tasks with check boxes.
What I'm looking for is an application that will also allow me to follow up on tasks (for examples task T = "send an email to John"), when complete it should also follow up on a response from John.
It should also help me organising tasks in different projects.
The only applications I found so far are so so and do not really improve upon the simple pen and paper list.
Do you have any suggestions?