Heartwood now has Future Mail — letters to your future self. Tap the plus button at the top to write one, then choose the day it opens: in six months, in a year, in five years, or on a date you pick yourself. You write it on the same familiar paper as your diary entries. Until that day comes, the letter stays sealed. The envelope shows the opening day and an optional line you write yourself, while the contents stay hidden. You can move the opening day if you change your mind, but you can't read the letter early. On the day you chose, the letter waits at the top of Today until you open it in a short ceremony. If you enable notifications for the letter, one arrives at your usual reminder time. Your first letter is included, and with Premium you can write as many as you like. Backups now contain your letters as well.

You can now choose how the app looks. Seasons stays exactly as it was, joined by calm palettes like Ink, Graphite, Botanical, Midnight, and Linen. Two dynamic themes change with the day: Day & Night shifts with sunrise and sunset, while Weather takes its color from the conditions saved with the entry you’re reading — so rainy October days look rainy, year after year. Dark Mode is no longer just black. Tinted lets the theme color the whole app, and anyone who prefers pure black can choose OLED. You can preview any theme across the whole app before deciding and choose whether it syncs to your other devices or stays on this one. Widgets follow the theme you choose. We’ve also fixed the paper background on diary cards: it now changes correctly when the system switches between light and dark mode. All themes except Seasons are part of Premium.

Heartwood Diary is now on your Home Screen and Lock Screen. The widget quietly shows that today is waiting for a line, and that this date carries something from an earlier year — without revealing a word of it. Your writing stays in the app. Three widgets to choose from — Heartwood Diary, Words for the day, and Countdown — with sizes for both iPhone and iPad. Touch and hold a widget to choose what it shows. “Write a line” is also available in Control Center and on the Lock Screen, and you can assign the control to the Action button. Say “Write a line in Heartwood Diary” to Siri and it lands at the end of today’s page. You don’t need to unlock to write. Siri can only add text — your entries are still visible only in the app.

We’ve improved stability and made refinements under the hood.

You can now choose a separate six-digit diary passcode, with optional Face ID or Touch ID. When enabled, your device passcode cannot unlock the diary. With Premium, you can now star quotes you want to keep and find them again in Settings → Daily content. The quote of the day now stays with you for the whole day and changes the following day. New, gentle milestones mark 10, 50, 100, and 200 days in your diary. Insights now show how your first patterns are taking shape. We’ve also improved text scaling and the way people and places are recognized in Insights.