Report updated Jul 6, 2026

공책 - AI 선생님의 그림일기 is an established lifestyle app that is completely free.

What is 공책 - AI 선생님의 그림일기?

Gongchaek is a lifestyle diary app for iOS that combines text and hand-drawn entries with an automated AI teacher feedback loop.

Users hire the app to recreate the nostalgic, supportive experience of childhood diary-keeping, using the morning teacher reply as a trigger to maintain daily journaling habits.

Current Momentum

v1.6 · 1mo ago

Maintenance
  • Released initial version in Feb 2026.
  • Maintained free-only access model.

Active Nemesis

EMMO - 日记与笔记

EMMO - 日记与笔记

By EMMO

Other Rivals

Shine - Timeline diary
团纸日记-把生活写成一本书
iMood-心情日记、待办清单
一叶日记·极简卡片心情记录日记
Chat with Me: Selfcare Journal
MyMemoir AI
时光之语
Ondo: AI Journal

7-Day Rank Pulse 🇺🇸

Lifestyle

No ranking data

Rating Pulse 🇺🇸

Gathering signals...

What makes this app unique?

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What Are The Key Features?

AI Teacher ReplyDifferentiator

Automated red-pen feedback delivered at 10 AM daily; drives DAU/MAU by anchoring the app as a morning habit.

Multimedia Diary EntryStandard

Supports text and hand-drawn sketches; builds a personal archive that increases switching costs.

How much does it cost?

Free
  • Free access to all current features

The app is currently free to use with no visible IAP or subscription gates, creating a revenue gap.

Who Built It?

Lifestyle

Enrichment in progress

Publisher profile available very soon

What other apps does SAHWI KIM make?

What do users think recently?

Analysis in progress, available soon

What is the competitive landscape for 공책 - AI 선생님의 그림일기?

Where is it available?

Localized markets (5)

United StatesBrazilJapanSouth KoreaMexico

How's The Lifestyle Market?

Targeting individuals seeking nostalgic, habit-forming digital reflection, Gongchaek operates in the lifestyle journaling space. The app is currently free with no IAP or subscription gates, which limits revenue potential but lowers the barrier to entry against paid rivals like EMMO.

Which niche is 공책 - AI 선생님의 그림일기 in?

Journaling Note Taking

to record daily memories with ai feedback

Note TakingJournalingGeneralFreemium IapEmerging

Explore the full Journaling Note Taking niche

Every app in this space (941 tracked), the niche's live rankings, and Marlvel's editorial take on the job-to-be-done.

Go deeper

The rivals identified

Nemeses(1)

This app competes directly by offering a structured, reflective journaling experience that emphasizes emotional tracking and personal security, mirroring the target's focus on intimate, daily record-keeping.

Contenders(4)

Shine competes by offering a data-driven approach to journaling, utilizing heatmaps and voice inputs to visualize the user's life timeline.

Differentiators

  • Includes a story heatmap that visualizes activity frequency, providing users with deep insights into their habits.
  • Supports voice-to-text diary entries, reducing the friction of manual typing for busy, on-the-go users.

Biograph App overlaps with the target by focusing on the narrative aspect of life-logging through collaborative storytelling and voice-to-text features.

LifeLeaf targets the same creative journaling audience by leveraging advanced AI to enhance diary entries with illustrations and book-style exports.

DailyRetro competes by positioning itself as a habit-forming journaling tool that uses reminders to ensure consistent daily engagement.

Same space(3)

This app shares the target's focus on private, self-reflective journaling through a chat-based interface.

Differentiators

  • Positions the AI as a self-care coach, focusing on mental health outcomes rather than just diary keeping.
  • Uses a simplified chat interface that lowers the barrier to entry for users intimidated by traditional journals.

AGSCalendar relates to the target by combining daily scheduling with motivational content to support user well-being.

Ondo competes by using conversational AI to facilitate journaling, creating a similar interactive experience to the target's teacher persona.

Differentiators

  • Uses conversational AI to prompt users, making the journaling process feel like a supportive dialogue.
  • Generates AI-powered postcards from journal entries, adding a creative, shareable layer to the user experience.

Compare 공책 - AI 선생님의 그림일기 against every rival

All rivals in one side-by-side table: identity, store metrics, ratings & sentiment, and strategic intel, plus a head-to-head page for each.

Go deeper

The outtake for 공책 - AI 선생님의 그림일기

Strengths to defend, gaps to attack

Core Strengths

  • Interactive teacher-reply loop creates a high-frequency morning habit
  • Nostalgic narrative structure differentiates the app from generic mood trackers

Critical Frictions

  • Zero monetization strategy limits long-term sustainability
  • Lack of advanced customization compared to category leaders

Growth Levers

  • Introduce premium teacher personas or specialized feedback themes as a subscription gate
  • Develop export-to-physical-book features to increase perceived value

Market Threats

  • Established journaling apps with massive user bases can replicate the feedback loop
  • High-frequency engagement metrics of competitors dwarf current market entrants

What are the next best moves?

highInvest

Test premium teacher personas because the current free model lacks revenue capture → prove subscription viability

The app is currently free with no IAP, leaving it vulnerable to competitors.

Trade-off: Pause development of new drawing tools — monetization is a higher existential priority.

A counter-intuitive read

The app's lack of monetization is not a weakness but a deliberate strategy to build a high-retention user base before introducing premium teacher feedback personas.

Feature Gaps vs Competitors

  • Sticker-based emotional tracking (available in EMMO but missing here)
  • Physical book export (available in 团纸日记 but missing here)

Key Takeaways

Gongchaek succeeds in creating a unique, habit-forming feedback loop, but the lack of a monetization model leaves it exposed to larger competitors, so the PM should prioritize testing a subscription tier for advanced teacher personas to prove revenue viability.

Where Is It Heading?

Mixed Signals

The journaling market is consolidating around apps that offer either deep emotional expression or physical archiving. Gongchaek must move beyond its current free-only state to secure its position against competitors like EMMO.

The app maintains a unique feedback loop, but the lack of monetization creates a sustainability risk that requires immediate strategic pivot.

Sources

  1. [1] App Store, source
  2. [2] Competitor Analysis, source
  3. [3] Competitor Analysis, source

Disclosure: Independent intel to help mobile builders succeed.

AI-powered analysis with editorial review, built from publicly available sources. Marlvel.ai is not affiliated with, endorsed by, or sponsored by 공책 - AI 선생님의 그림일기, its developer, the app publisher, Apple, or Google Play. All trademarks, logos, and screenshots referenced remain the property of their respective owners.

What's new

The report shifts focus from product-led retention to monetization strategy, identifying the current free-only model as a critical sustainability risk.

added

Monetization as a critical weakness

added

New feature gaps identified

shifted

Strategic pivot to revenue viability

Cite this report

Marlvel.ai. “공책 - AI 선생님의 그림일기 Intelligence Report.” Updated Jul 6, 2026. https://marlvel.ai/apps/greenonion-notebook

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