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The Easiest Way to Keep a Line from a Paper Book
If typing breaks your reading flow, mark or photograph instead. Different media still work if you leave a cue you can find again.
Do ‘Lucky’ Lottery Stores Actually Exist?
Jackpot retailers show up on maps for a reason. That still does not mean the shop changes your odds — symbol and probability are different things.
Reading Without Pressure — What Matters More Than a Book Goal
A '50 books this year' goal can ruin reading. What lasts isn't speed — it's keeping a relationship with books and leaving traces at a pace you can sustain.
Why You Shouldn't Treat Lottery Tickets as an Investment
A negative-expected-value product does not belong in a portfolio. Kept as entertainment, the relationship and the budget stay healthier.
What You See When You Look Back at a Year of Reading
Even a count of books helps. When genre and timing show up, next year's reading gets clearer — but looking back needs traces left along the way.
Saturday Night and the People Who Check the Lotto
On draw nights, the same screens open across the country. More than winning, that short ritual becomes everyday lotto — if you keep it light.
Minimum Reading Notes for People Who Never Keep Them
Skip the perfect review. One sentence or one page photo — only notes you can actually keep become a habit, and only habits help later.
Auto vs Manual Lotto Numbers — Why People Choose
The odds are identical, yet the counter still splits into auto and manual. The difference is how choosing feels — and whether you have a routine.
Why the Pile of Unread Books Keeps Growing
Unread shelves aren't proof of laziness — they're inventory of the self you hoped to be. Sorting starts with visibility, not guilt.
Five Common Myths About the Lottery
Hot numbers, cold numbers, lucky stores… lottery folklore is full of stories. Here is where fact ends and interpretation begins.
Why Finished Books Fade from Memory
You remember that you finished it — not what it said. Often the issue isn't memory; it's that you left no retrieval cues behind.
How Low Are the Odds of Winning the Lotto Jackpot?
Choosing 6 numbers from 1–45 means about 8.14 million combinations. Seeing that number clearly — and what it does not promise — changes how you treat the game.
Smart Lotto — How to Read Cold Numbers and Frequency Stats
Cold numbers and hot frequencies are fun to watch. They are a record of the past — not a promise about next week’s draw.
BbitbbitBook — Local Mode Without Login vs Signed-In Mode
Start without an account, or sign in to sync across devices. Try lightly first; settle firmly when the habit proves itself.
Smart Lotto — Build Your First Number Strategy as a Beginner
Your first strategy does not need to be perfect. Use few conditions, save them, and reuse the same method each week.
BbitbbitBook — A 5-Minute Routine After Finishing a Book
You don't need a full review. Register, mark finished, leave one line — five minutes while the book is still warm.
Smart Lotto — A Lottery App You Can Use Without Signing Up
A light hobby deserves a light entrance. No account wall — open the app, use stats and generation, and keep strategies on your device.
BbitbbitBook — Use the Same Library on iOS and the Web
Log on mobile, continue on desktop. Sign in and your data syncs — so reading and organizing can live in different places.
Smart Lotto — Generate Up to 5 Games at Once
Buying several games is fine when the count is decided first. Generating multiple tickets under one rule is about less busywork — not about chasing luck harder.
The Real Reason Poker Players Need Data
Memory is biased. Wins feel like skill, losses feel like bad luck. Data removes that bias — and that's what makes improvement possible.
BbitbbitBook — Highlight and Underline on Page Photos
Draw highlighter and underlines on a page photo so paper-book markup lives in the app — especially when you cannot mark the real page.
Smart Lotto — How to Find Nearby 1st-Prize Lottery Stores
Hunting a 'lucky store' is usually about story, not odds. Enjoy the story lightly, keep the trip short, and do not let place become an excuse to overspend.
My Bankroll Beginner's Guide — Where to Start with Poker Tracking
For players new to tracking or just starting poker. What to log first, which stats to look at, and how to build a review habit that actually improves your game.
BbitbbitBook — Pull Sentences from a Page Photo with OCR
When typing a quote feels heavy, snap the page and extract text with OCR into a memo — keep the image and the searchable line together.
Smart Lotto — Balancing Picks with Odd/Even Ratio and Sum Range
Odd/even balance and sum ranges do not guarantee a win. They help you avoid combinations that feel extreme so the ticket still feels like yours.
GTO vs. Exploit — How AI Analysis Helps Your Real-Game Decisions
GTO is mathematically optimal strategy. My Bankroll's AI analyzes hands from a GTO perspective and delivers actionable insights you can apply at the table.
BbitbbitBook — Collect Bbit Characters with Carrots
Logging books earns carrots. Spend them to collect Bbit characters — a light collecting layer on top of reading records.
Smart Lotto — Narrowing Numbers with Fixed and Excluded Sets
Must-include and must-exclude numbers do not change the odds. They leave a personal rule on the ticket so choosing feels less random and less rushed.
Position Profit Analysis — There's a Specific Spot Where Your Chips Are Leaking
Position is one of poker's most important variables. My Bankroll's position-by-position stats show exactly where your leaks are.
BbitbbitBook — Organize Your Library: Want, Reading, Finished
Three statuses keep 'what to read next' and 'what I'm reading now' from getting mixed up.
Smart Lotto — A 10-Minute Saturday Routine Before the Draw
A short pre-draw habit: decide numbers at home, keep the budget fixed, and leave the counter for buying — not for inventing a strategy under pressure.
Data-Driven Session Management — When to Stop Playing Poker
When to end a session is an important decision in poker. My Bankroll's session-length analysis shows your optimal play window — in data, not instinct.
BbitbbitBook — Register a Book in 30 Seconds with the Back-Cover Barcode
No need to type the title. Scan the ISBN barcode and the book is searched and ready to add — registration has to be light for logging to stick.
My Bankroll Pricing — Free, Plus, and Pro Plans Explained
My Bankroll is free to start. Session logging and basic stats are free. Advanced analytics and AI hand analysis are available on paid plans.
My Bankroll PWA — Install a Poker Tracker Without an App Store
My Bankroll is a PWA. Install it to your iOS or Android home screen in seconds — no app store required. Log your session the moment the game ends.
My Bankroll Hand Replayer — Review Hands on a Visual Poker Table
Replay hand history visually on a poker table layout. Step through each street's action and review decisions in context — not just in text.
What Is BB/100 — The Most Accurate Metric for Measuring Poker Skill
BB/100 is your average profit per 100 big blinds. It normalizes across stakes and volume — making it the standard measure of poker performance.
Variance in Poker — How to Tell If You're Losing from Skill or Luck
Variance is the spread of results around your expected value. Short-term results alone can't tell you if you're playing well. Data can.
July 1, 2026 — First Domino 1.0.0 Ships
An idea born in 2019 became an app on July 1, 2026. A 7-year assignment, finally submitted.
The Play Store Wall — Business Registration and the 14-Day Tester Requirement
Two barriers blocked the Android launch: in-app purchases require business registration, and closed testing requires 12 testers for 14 days. iOS launched first.
Implementing In-App Purchases with RevenueCat — My First Time in Flutter
IAP was familiar in iOS development, but Flutter was a first. The journey to finding RevenueCat.
Black and Gold — Designing for Focus
First Domino's color palette wasn't just a personal preference — it came from the app's core purpose: focus.
Reviving a 7-Year-Old Idea — This Time with Flutter
After analyzing competing apps and finding them lacking, I chose Flutter to build First Domino for both iOS and Android at once.
The One Thing — The Book That Changed Me 7 Years Ago
In the summer of 2019, reading The One Thing sparked an app idea. That idea sat buried for 7 years.
My Bankroll Free Equity Calculator — Instant Texas Hold'em Win Rate Math
Enter hero hand, villain hand, and board cards. Monte Carlo simulation calculates your equity instantly. Free to use, no account required.
My Bankroll AI GTO Analysis — Claude Coaches Your Hands in Real Time
Enter a hand and Claude AI analyzes it from a GTO perspective in real time. Expert-level hand review without an expensive coach.
My Bankroll Statistics — Finding Exactly Where You Lose Money
Position-by-position, time-of-day, and session-length profit breakdowns are calculated automatically. Weaknesses you only sensed appear as numbers.
My Bankroll — Visualize Your Results Like a Stock Chart
Log your sessions and watch your bankroll rendered as a stock-market-style chart. The first step to understanding your poker results objectively.
My Bankroll — A Data-Driven Service for Serious Poker Players
Log every session, read your statistics, get your hands analyzed by AI. My Bankroll helps poker players grow their skills with data.
First Domino — Building a Daily Routine Around One Focus
How to use First Domino as a daily routine anchor. Check today's one thing in the morning, mark it complete in the evening.
BbitbbitBook Dev Log #12 — Web Version and Android: What's Next for BbitbbitBook
From a landing page to a full web app. And Android in Kotlin, in progress. The story of BbitbbitBook's platform expansion.
First Domino — The Top-Down Goal Structure
First Domino's core feature is a top-down goal structure: 5 years → this year → this month → this week → today.
First Domino — Why You Should Focus on Just One Goal
First Domino (단하나) lets you set only one goal at a time. Here's the core philosophy behind that constraint.
Why Bbitbbitbook Was Built — The Problem of Reading Without Remembering
Reading a lot while retaining little is a common frustration. Connecting reading with small records is how memory starts to stick.
Bbitbbitbook — Reading Statistics Feature
Beyond a book list: monthly volume, genres, completion rate, and pace — a quieter way to see what kind of reader you are.
Bbitbbitbook — The Reading Passbook Feature
A passbook metaphor for reading: finishes and notes deposit carrots so effort stays visible as a growing balance, not a vanished evening.
Bbitbbitbook — Photo Memo Feature
Snap a page when a passage hits, add a short line, and keep it bound to the book — fast capture that you can find again.
BbitbbitBook Dev Log #11 — App Crashes on Launch: What Crashlytics Found
Shortly after 1.2.0 shipped, a review appeared: 'The app closes immediately when I open it.' The process of finding the cause through Crashlytics logs.
Why 3weeks Was Built — The Pattern Behind Resolution Failures
Resolutions fail repeatedly for predictable reasons: goals are too vague, timeframes too long. 3weeks addresses this with a concrete 21-day unit.
BbitbbitBook Dev Log #10 — New Books, Monthly Reading, and a Redesigned Home Tab: 1.2.0
The home tab was completely rebuilt. New releases and popular titles via the National Library API, plus this month's reading status at a glance.
3weeks Streak Structure — How Consecutive Records Create Motivation
3weeks resets to zero if you miss a day. This strict structure is exactly what motivates daily execution.
Habits That Work Well with 3weeks
3weeks is built around a daily consecutive check structure. Habits that are doable every day with clear completion criteria are the best fit.
Getting Into Whisky: What Should You Start With?
A beginner's guide to whisky for anyone just starting out. Which bottles to begin with, and how to drink them.
3weeks — Why 21 Consecutive Days?
3weeks locks the goal period to 21 days. Here's the habit formation theory behind that choice.
Smart Lotto's Tail Digit Condition — A Number Selection Strategy
A tail digit is the ones place of a lotto number. People care about it because they like reading patterns — not because it unlocks the draw.
How Smart Lotto Differs from Auto-Generated Numbers
Auto tickets and condition-based tickets share the same jackpot odds. What differs is the experience of choosing — and that difference is enough for some people.
BbitbbitBook Dev Log #9 — After a Year Away: Liquid Glass and Version 1.1.0
The last update before the break was February 2025. In 2026, returning to development meant replacing the entire tab bar and applying a new design system.
Smart Lotto — Save Your Own Number Strategy
Re-entering the same filters every week quietly ruins the habit. Saving a strategy is for repetition — not for claiming a smarter path to the jackpot.
Smart Lotto — Location-Based Lotto Store Finder
After the numbers are ready, picking a nearby place to buy keeps the habit light. A distant 'lucky' shop is optional color — not a requirement.
Smart Lotto Statistics — 1,200+ Draws of Winning Data Inside the App
Historical draw data lives in the app so you can browse quietly. It is material for choosing — not a dashboard that predicts next week.
Smart Lotto — The Statistics-Based Condition System
Conditional random matches plain random on jackpot odds. What changes is the experience: you meet chance inside rules you agreed to first.
BbitbbitBook Dev Log #8 — Statistics and Categories: Turning Reading Into Data
Statistics was the most-requested feature from users. Adding yearly and monthly charts, plus genre classification by ISBN, made reading data meaningful.
BbitbbitBook Dev Log #7 — Highlighting Photos: OCR and Image Editing
Taking a photo is much faster than typing. That starting point led to OCR text extraction and then to highlighter and underline image editing.
BbitbbitBook Dev Log #6 — Scanning Books: The World of ISBNs
For readers using physical books, barcode scanning to register a book seemed obvious. But ISBN wasn't as simple as I expected.
BbitbbitBook Dev Log #5 — Use Without Login: Local Mode and Authentication Design
Apple Sign-In was mandatory. Local mode was a choice. Implementing both revealed problems — one of which remains unsolved.
BbitbbitBook Dev Log #4 — May 1, 2023, 12:36 AM: First Launch
May 1, 2023, 12:36 AM — BbitbbitBook appeared on the App Store. Two and a half months after development began.
BbitbbitBook Dev Log #3 — Book Search API Battle: Naver vs. Kakao vs. Aladin
Book search required a book data source. Naver, Kakao, National Library of Korea, Aladin — here's what using each API taught me.
BbitbbitBook Dev Log #2 — What I Learned from a Competitor, NFTs, and the Reading Passbook
A plain reading journal app had no differentiation. After studying a competitor, adding NFT characters, and designing the Reading Passbook, BbitbbitBook found its identity.
BbitbbitBook Dev Log #1 — The Problem of Finishing a Book and Remembering Nothing
I started reading one or two books a month. After finishing them, I was left with 'it was good' and nothing more. That frustration became an app.
3weeks Dev Log #10 — Finally: iOS and Android Simultaneously
An app that started as iOS-only in 2019 launched on Android in 2026. Flutter made it possible.
3weeks Dev Log #9 — Making It a Game: Badges and Statistics
I wanted to move past a plain check-off app. Collecting badges, seeing your progress in stats, watching habits accumulate visibly — that was the goal.
3weeks Dev Log #8 — From UIKit to Flutter: What the Tech Stack Switch Actually Looks Like
Swift UIKit + Realm to Flutter + Hive. Rebuilding the same features in a different language and framework was more interesting than I expected.
3weeks Dev Log #7 — Four Years Later, Rebuilding in Flutter
Decided to replace the Swift UIKit app entirely with Flutter. The technical reasons were secondary — I wanted to make the app genuinely more fun.
SMART LOTTO Dev Log #10 — A Korean Lottery App That Disappeared From Korea
The App Store reviewer decided my app was gambling. I pushed back, worried about getting blacklisted, and eventually complied — which made my app invisible in South Korea.
3weeks Dev Log #6 — After 1.1.3, Four Years of Silence
May 2, 2023, 6:26 AM — version 1.1.3 shipped. That was it. Nearly four years went by without touching the app.
SMART LOTTO Dev Log #9 — Android Launch: Find 12 Testers
To publish on Google Play, new personal developer accounts must run a closed test with at least 12 testers for at least 14 days. An iOS developer trying to find 12 Android users.
3weeks Dev Log #5 — Saying It Out Loud Helps: Voice Memo Feature
Research suggests that vocalizing something helps encode it. So I added a voice recording feature — record a message, hear it every time you check in.
SMART LOTTO Dev Log #8 — Rebuilding with Flutter and Claude Code
I rebuilt an app with no source code. This time in Flutter. With Claude Code as a development partner. June 11, 2026 — version 1.2.0 shipped.
3weeks Dev Log #4 — Without a Reward, Habits Don't Stick
I learned that habit formation requires a reward system. The app can't give rewards directly. But it can let users define their own — and that turned out to matter.
SMART LOTTO Dev Log #7 — The Source Code Is Gone
Deleted from Bitbucket. MacBooks reformatted. The app is live on the App Store, but the code exists nowhere on earth.
3weeks Dev Log #3 — July 25, 2019, 4:58 AM: First Launch
4:58 in the morning. The App Store approval email arrived. That's what it feels like when your app enters the world.
SMART LOTTO Dev Log #6 — Two Years of Silence, Then a Bug
The last update was October 17, 2023. I didn't touch the app for over two years. Then in early 2026, I discovered it had stopped fetching draw data entirely.
3weeks Dev Log #2 — The 21-Day Rule: Consecutive, Reset, Complete
The app had one core rule: 21 consecutive days. Miss one day and you're back to zero. Simple as it sounds, how you implement that rule is what the whole app is built on.
SMART LOTTO Dev Log #5 — Two User Reviews That Built Two Features
I knew what an excluded number was. I had no idea what a tail digit was. Two user reviews added two features I wouldn't have thought to build.
3weeks Dev Log #1 — How a Single Talk Became an App
In 2019, I watched a talk and decided to build an app. I didn't expect 'just keep doing it for 21 days' to stay in my head this long.
SMART LOTTO Dev Log #4 — Why Statistics Were Slow, and How a Dictionary Fixed It
Iterating over 1,200 Realm objects on every screen load was noticeably slow. Pre-computing results into a Dictionary made it instant. An obvious fix — but you have to feel the problem first.
SMART LOTTO Dev Log #3 — A QR Code Feature That Blocked App Store Approval
I had to hide a feature I'd built — not remove it, just hide it — before the App Store review would pass. Sometimes reviewers refuse to believe what your app actually is.
SMART LOTTO Dev Log #2 — Why I Bundled 1,000 Draws Inside the App
Calling an API 1,000 times every time the app opens is ridiculous. I knew that from the start — and found a three-step solution.
SMART LOTTO Dev Log #1 — December 2020: Why a Lottery App?
December 16, 2020, 12:22 PM — I uploaded the first build to TestFlight. About two weeks after I started development.
BbitbbitBook — Why I Built a Reading App That Already Exists
Reading journal apps already exist. I built one anyway. Because the one I wanted to use wasn't there.
3weeks — Building the Hypothesis That 21 Days Is Enough
Habit apps are everywhere. Most of them fail. Here's why the 21-day challenge concept works — and what building it as an app taught me.