OmniFocus is the gold standard for serious GTD practitioners on Apple platforms — a deeply configurable task manager with projects, tags, contexts, custom perspectives, forecast views, and review workflows. Developed by the Omni Group since 2007, it handles thousands of tasks without losing clarity. Its Custom Perspectives let power users create filtered views like "all delegated tasks due this week" — a level of query power no other consumer task app offers. For users who invest in learning it, OmniFocus becomes a deeply personal productivity operating system that scales from student to CEO.

Reference:

OmniFocus on Wikipedia

https://en.wikipedia.org/wiki/OmniFocus