Best To-Do List & Planner Apps for iPhone Duo (2026)

The iPhone Duo went on sale on 23 October 2026 with iOS 27.1. Apps built with the iOS 27.1 SDK fill the 7.6-inch inner display; everything else runs in a phone-sized window with black borders. Apple marks the adapted ones with a "Made for iPhone Duo" label in the App Store, and from April 2027 every app submission has to include iPhone Duo screenshots. So the question for a planner is not whether it opens on the Duo (they all do) but whether unfolding the phone gives you anything a normal iPhone cannot.

This list only includes apps whose current release notes describe an iPhone Duo layout. Weeklane is our own app; its entry says plainly what is shipping and what is still on the way.

At a glance

Things 3: a sidebar for your lists

Things 3.25.1 (22 October 2026) is the most thorough adaptation so far. The release notes describe a dynamic layout for every pose: closed, open, folded like a book, and Split View next to another app. Unfolded, a sidebar shows all your areas and projects while the main pane keeps Today or Upcoming open, which is the iPad layout brought to a phone. Things is a one-time purchase per platform ($9.99 on iPhone), so the Duo version costs nothing extra if you already own the iPhone app.

Best for: people who already run their life in Things and want the iPad view in their pocket. Not for: anyone who wants a week laid out day by day; Things is a list-and-project app, and its Upcoming view is a scrolling list rather than a week.

Structured: a timeline that follows the fold

Structured 4.6.5 (22 October 2026) added iPhone Duo support: the timeline relayouts as you fold and unfold, and the Focus Timer has a layout for the book and tabletop positions, so you can stand the half-open phone on a desk and run a timer while you work. Structured is a daily planner: tasks sit on a vertical timeline with times and durations, with a free tier and a Pro upgrade.

Best for: time-blocked days and the tabletop Focus Timer. Not for: planning a whole week at once; the day is the unit.

Fantastical: calendar and tasks together

Fantastical 4.2.4 (23 October 2026) lists "Added support for iPhone Duo" in its notes, and Apple used Fantastical as one of its launch examples. On the inner display you get the calendar, your tasks and the weather on one screen, with Todoist tasks synced in if you use that. The app is free with a Premium subscription for most of the calendar features.

Best for: calendar-first people whose tasks are mostly appointments. Not for: a simple checklist; Fantastical is a calendar that can show tasks, not a to-do list.

SuperPlanner: two displays, two jobs

SuperPlanner 3.1 (7 October 2026) was ready before the phone shipped. Its notes are specific: the outer display shows your day in hand; open the phone and a sidebar sits beside a full-height timeline, with a Day Summary alongside in landscape; fold it halfway and the current activity's tasks appear on the other half; sectioned lists spread into two columns. It requires iOS 27.1 on the Duo. Free with a Pro subscription.

Best for: visual day planning with the half-fold used as a second screen. Not for: a weekly view or a no-setup list.

Solarday: intention and list side by side

Solarday 1.4.1 (17 October 2026) says its Day and Do views sit side by side when the phone is unfolded, so your daily intention and your list are in view together; folded, it works as before. It is a small, calm daily planner with a free version and a Supporter tier for themes.

Best for: one intention and a short list per day. Not for: recurring tasks, reminders or anything beyond today.

Apple Reminders: free and already full-screen

Apple's own apps, Reminders included, use the inner display without borders. Reminders has lists, smart lists, widgets and Siri, and it is free. What it does not have is a week: you can make a "this week" smart list, but the days are not laid out next to each other.

Weeklane: iPhone Duo update in development

Weeklane is our app, so read this as the maker's description. Weeklane's iPhone Duo update is in development. Until it ships, Weeklane runs in the standard phone layout on the iPhone Duo, with black borders on the inner display. Task Lock (apps stay locked until today's tasks are done) and Plan with AI (Claude or ChatGPT reorganise the week) already work on the iPhone Duo, because they do not depend on the layout.

We will update this page the day the iPhone Duo update is live on the App Store. The weekly planner is free; Pro is $4.99 a month or $34.99 a year with a 7-day free trial.

Not adapted yet (as of 28 October 2026)

These popular to-do apps had no iPhone Duo mention in their current App Store release notes when we checked. They still work on the Duo, in a phone-sized window with black borders on the inner display. Expect most of them to update within weeks; this list will be revised as they do.

• Todoist version 26.10.27 (26 October): no iPhone Duo mention in the release notes.
• TickTick no iPhone Duo mention in the current release notes.
• Tiimo version 3.70.1 (21 October): Apple Watch features, no iPhone Duo mention.
• Tweek, Sunsama, Any.do, Notion no iPhone Duo announcement found at the time of writing.

How to tell whether an app is really adapted

1. Look for the label. The App Store marks adapted apps as made for iPhone Duo. No label means the app has not been rebuilt with the iOS 27.1 SDK.
2. Read the latest release notes. Developers who did the work say what changes when you unfold the phone. "Bug fixes and improvements" means nothing changed.
3. Unfold it and look at the edges. Black borders on the inner display mean the app is running in its iPhone layout.
4. Try the half-fold. The best adaptations do something with the book and tabletop positions, such as a timer or a second pane, rather than just stretching.

Which one should you pick?

• You plan by project. Things 3. The sidebar is exactly what the bigger display is for.
• You plan by hour. Structured or SuperPlanner, depending on whether you want the tabletop timer or the half-fold task pane.
• You live in your calendar. Fantastical.
• You want one intention a day. Solarday.
• You plan by the week. Weeklane works on the iPhone Duo today in the standard phone layout; its iPhone Duo update is in development.
• You want to spend nothing. Apple Reminders, or Weeklane's free weekly planner.

A week you can hold open

Weeklane shows your week as seven short day lists on iPhone, iPad, Mac and Android. The weekly planner is free; Weeklane Pro adds Task Lock and Plan with AI.

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