Show HN: I built a calendar app that gives each event its own to-do list

Zesfy is an iPhone productivity app built around combining calendar scheduling with task management. Its central feature lets users group several tasks into a single calendar event, so an appointment or work session can contain its own actionable checklist. Tasks can be scheduled in a few taps, highlighted when important, and organized by status. Subtask completion automatically updates overall task progress, giving users a way to track how much of a planned session is done. Calendar groups can also be filtered to reduce clutter and focus on selected sets of events.

The app has expanded beyond its basic calendar-and-task setup with features such as recurring tasks, daily summaries with reminders and progress updates, notes within subtasks, and pinned tasks. Recent version notes emphasize interface, scheduling, and performance refinements, including changes to the weekly task view and calendar display. Zesfy is free to download, with weekly, monthly, and yearly Pro subscriptions; it requires iOS 17.2 or later. The developer says the app collects no data, though Apple notes that this privacy information has not been verified.