BbitbbitBook Dev Log #2 — What I Learned from a Competitor, NFTs, and the Reading Passbook

Features Alone Aren't Enough

During planning, one concern kept coming up.

Reading records, memos, book search — these are useful features. But if competing apps offer the same things, there's no reason for anyone to choose mine.

I needed an answer to: "why should anyone use BbitbbitBook specifically?"

What I Learned from a Competitor

Around that time, a reading app called 북적북적 (Bookjuk Bookjuk) was gaining popularity in Korea.

I looked at it closely. The core features weren't unusual. But there was one distinctive mechanic: logging a book added height to a virtual bookshelf proportional to the book's thickness, and reaching certain heights unlocked characters to collect.

The differentiation wasn't in functionality — it was in experience.

Reading records became a collecting journey rather than a data entry task. That made people want to come back to the app.

NFT Characters in the App

I happened to own several NFTs at the time.

NFTs typically grant usage rights to the buyer — including commercial use in certain collections. I had characters called "Bbitbbit" (삐삐) in those NFTs. Using them as collectibles in a reading app felt like a natural fit.

That's how the app got its name: BbitbbitBook. You read books, and by reading you collect Bbitbbit characters.

With a collectible element in place, the app's direction became clear. Reading earns something. Having something to earn makes you want to keep going.

The Reading Passbook Idea

While designing the character collection system, I came across an interesting cultural practice.

Korean elementary schools sometimes use "reading passbooks" — physical notebooks designed to look like bank passbooks where children log every book they read, as if making deposits.

The analog metaphor was perfect for the app.

Read a book → a transaction appears in your Reading Passbook → you receive Carrots (in-app currency) → Carrots unlock Bbitbbit characters.

The flow was coherent. Reading records weren't just data — they were deposits in a growing account.

Why Carrots?

The character name was Bbitbbit, which had a rabbit-like quality. Rabbits eat carrots. So the in-app currency became Carrots.

A small decision, but it gave the app's world consistency. The character, the currency, and the passbook concept all sat inside the same story.

Two Axes: Practical and Fun

At this point the app had two clear dimensions:

Practical: book search, memo recording, reading history, statistics. Features that actually support the reading life.

Fun: Carrot earning, Bbitbbit collection, Reading Passbook. Elements that make you want to open the app.

Both are necessary for an app people keep using. Useful-only apps get used when necessary and forgotten. Fun-only apps get abandoned when the novelty fades. The combination is what sustains engagement.