Email, calendar & tasks
OmniPlan is what you open when a task list stops answering the question you actually have, which is normally: if this one job slips three days, what else moves? It draws real Gantt charts, tracks dependencies and the critical path, levels resources so one person is not booked twice on the same afternoon, and keeps baselines so the plan you promised sits next to the plan you have.
The $199.99 Standard licence is one payment and covers Mac, iPhone, iPad and Vision Pro together. Omni is unusually direct about where that stops: the licence includes every 4.x update, and a future major version will be a paid upgrade with a discount for existing owners. Pro at $399.99 adds shared-server collaboration and the deeper scheduling and analysis work. Since the $199.99-a-year subscription grants Pro, the comparison worth doing is a year of subscription against owning Pro outright.
Do not buy this to organise personal projects — a to-do app does that, and OmniPlan asks for enough setup that you will resent it for a grocery list. Do not buy it for a team living on Windows either. And take the trial seriously: there is a 30-day money-back guarantee, and $200 is a lot to spend discovering you only needed a dependency chart twice a year.
Canary Mail
OmniFocus 4
2Do
BusyCal