You wont find a more flexible app for doing GTD the way you want to do it.
I use this app multiple times daily. It helps me keep track of everything and lets you sort and organize your tasks quickly and efficiently to focus on your next actions.
Im surprised this doesnt show up in the top apps list consistently. The author has made steady improvements over the years. This is a awesome, well-supported app! And you can access it from anywhere - iPhone, iPad, or desktop!
FitBit User about Toodledo, v3.3.6