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Sunday, October 25, 2026

5:21:40 AM

3

New folder, My travels

Planning a trip? I mapped out everywhere I've been worth a look before you go.

New folder, My travels

Planning a trip? I mapped out everywhere I've been worth a look before you go.

Say hi to Geronimo

My new voice AI. Just say "Geronimo" or "Hey Geronimo" to browse my work hands free.

I added MP3 Player

Made you a playlist. Hit play and take a listen.

Back

Back

Back

Hearu turns a private diary into a conversation.

Write about your day, pick how it felt, and Bongbong one Al character with one consistent
personality writes back. Every entry and reply is kept, locked, and ready to revisit.

Keywords refresh every five minutes, and each one opens a board that lives for thirty unless people keep talking. Every post and comment buys the board more time.

Role

Team Side Project

Duration

2026

Team

Mobile App / Al Journaling

Focus

Strategy, UX/UI, Al Experience

Challenge

Diaries keep your day

But no one ever writes back

Keeping a diary is a long-loved habit, yet most people stop within weeks. Writing into silence gives little reason to come back. Some turn to Al chats instead, where replies come fast but get buried among everything else.

A diary needed a reason to return, without turning into another chatbot.

Research

The problem wasn't writing

It was the silence after it

I surveyed 120 diary writers and reviewed diary apps, Al chat services, and character apps to understand why people stop keeping a diary.

Diary apps

Private, but silent

Entries are kept safely, but nothing ever answers back.

Entries are kept safely, but nothing ever answers back.

Al chat

Responsive, but fleeting

Replies feel immediate, but threads scroll away and are hard to revisit.

Replies feel immediate, but threads scroll away and are hard to revisit.

Character apps

Warm, but not a diary

Characters feel friendly, but rarely keep a private record worth rereading.

Characters feel friendly, but rarely keep a private record worth rereading.

The Diary

Kept safely, but writing into silence is hard to sustain day after day.

The Al Chat

Answers instantly, but the entry scrolls away with everything else.

How might we?

How might we give every diary entry a warm reply, so writing feels worth coming back to?

My Role

I defined the product end to end from concept to a working MVP

I led product design across
web and Chrome extension

As the product designer, I shaped how an Al character could write back to every diary entry.

My work covered product strategy, information architecture, the diary-writing flow, the emotion framework, Al character and tone, archiving, privacy, and the Ul system.

01

Concept and value proposition

Concept and value proposition

02

IA and navigation

IA and navigation

03

Emotion selection framework

Emotion selection framework

04

Al character and tone system

Al character and tone system

05

Reply generation and loading

Reply generation and loading

06

Calendar-based diary archive

Calendar-based diary archive

Key Solutions

Three steps from writing a diary to receiving a reply

Hearu connects writing, receiving Bongbong's reply, and rereading in one gentle loop.

  • Key Solution 01

    Write without blank-page pressure.

    The home screen asks the way a friend would - "오늘 있었던 일을 봉봉이한테 다

    "al!" Drafts are saved, so stopping halfway is safe.

    The emotion is chosen after writing, not before.

    Design Decision

    Let users express first and name the feeling second.

    Design Principle

    Lower the barrier to starting without lowering the depth of what's written.

  • Key Solution 02

    A reply letter from Bongbong, not a chatbot answer.

    The wait is framed as a letter being written and delivered. Replies acknowledge rather than counsel, in one of two speaking styles.

    Users can rate every reply, giving a signal for tuning tone.

    Design Decision

    Turn generation latency into a character moment instead of a spinner.

    Design Principle

    Acknowledge, don't counsel.

  • Key Solution 03

    A diary worth returning to.

    Every entry is stored with its emotion and Bongbong's reply, browsable by calendar and day timeline.

    A PIN lock keeps the diary private from the very first screen.

    Design Decision

    Store the entry and its reply as one record, so the archive always shows both.

    Design Principle

    Privacy is a core feature, not a setting.

  • Key Solution 01

    Write without blank-page pressure.

    The home screen asks the way a friend would - "오늘 있었던 일을 봉봉이한테 다

    "al!" Drafts are saved, so stopping halfway is safe.

    The emotion is chosen after writing, not before.

    Design Decision

    Let users express first and name the feeling second.

    Design Principle

    Lower the barrier to starting without lowering the depth of what's written.

  • Key Solution 02

    A reply letter from Bongbong, not a chatbot answer.

    The wait is framed as a letter being written and delivered. Replies acknowledge rather than counsel, in one of two speaking styles.

    Users can rate every reply, giving a signal for tuning tone.

    Design Decision

    Turn generation latency into a character moment instead of a spinner.

    Design Principle

    Acknowledge, don't counsel.

  • Key Solution 03

    A diary worth returning to.

    Every entry is stored with its emotion and Bongbong's reply, browsable by calendar and day timeline.

    A PIN lock keeps the diary private from the very first screen.

    Design Decision

    Store the entry and its reply as one record, so the archive always shows both.

    Design Principle

    Privacy is a core feature, not a setting.

Home & Writing

A prompt, not a blank page

Diary apps open on an empty form. Hearu opens on Bongbong, greeting you by name.

A friendly prompt and a week-at-a-glance strip make starting today's diary feel as easy as telling a friend.

Bongbong's Reply

A letter, not a loading spinner

Waiting on Al usually means watching a

spinner.

Bongbong's reply arrives like a letter (!) and sits right under your entry, written in

his own hand.

Archive

A history of being heard

Most diaries are written once and rarely reread.

A calendar color-coded by emotion and a timeline for each day keep every entry and its reply together - even several in one day.

PIN Lock

Private from the first screen

A diary only works if it feels safe to be

honest.

The lock is the first thing you see, guarded by Bongbong, so privacy is felt before a

single word is written.

Outcome

A reply made the diary worth coming back to.

In a 4-week beta with 150 users, Hearu showed higher retention and longer entries than participants' previous diary habits.

+42%

01

Day-7 retention

vs. previous diary apps

3 → 9 min

02

Average writing time per entry

87%

03

Replies rated positively

4.6 / 5

04

Beta satisfaction score

"People wrote longer when they knew Bongbong would read it, though reply quality still needs long-term validation."

"People wrote longer when they knew Bongbong would read it, though reply quality still needs long-term validation."

Reflection

The hardest problems live outside the visible UI.

Designing the reply raised questions the interface alone can't answer: response consistency, off-tone or unsafe replies, high-risk entries, and how people export or delete what they've written.

Before scaling, Hearu needs safety responses, clearer limits for the Al, data controls, and a way to evaluate reply quality.

Next project

Everyone Waiter