NextThing for GTD is described as 'NextThing is a task management app built around the Getting Things Done (GTD) methodology. It gives you a complete system to capture, clarify, organize, and review everything on your mind' and is an app. There are nine alternatives to NextThing for GTD for a variety of platforms, including Mac, iPhone, Android, Web-based and Windows apps. The best NextThing for GTD alternative is Mindwtr, which is both free and Open Source. Other great apps like NextThing for GTD are Things, Taskwarrior, OmniFocus and Nirvana.