일오삼 is a small independent team based in Korea. We build and operate Bballi.
On a family trip to an area with a lot of tourists, I ran into a public toilet that was dirty and hard to use. It made me wish every tourist visiting Korea could use a toilet comfortably, since that kind of experience shapes how people feel about the country. Later, I learned the story behind how Korea’s public toilets got to where they are today, and I wanted to help keep that progress going. That’s why I started Bballi.
— 이윤재, 일오삼 대표
Beyond Bballi, 일오삼 also works as a UI/UX studio that designs and builds digital services across language, education, big data and AI.
Our founder has spent 14+ years planning platform services for public-sector, financial and education organizations, turning complex requirements and data into screens and structures that hold up in real operation.
Finding a public toilet when you actually need one is harder than it should be, especially in a language you do not read fluently. So we focused on doing one thing well: showing the nearest usable toilet in seconds, free, in your language, without an account.
We are not a large company. We are a small team that reads every message sent to bballiapp@naver.com, and we would rather hear about a problem than not.
What we do
As a UI/UX studio, we work through the full cycle of planning a digital service: not just screens, but the policy and structure behind them.
Service policy & information architecture
Defining how a service should behave, then structuring it so the behavior stays consistent.
UX/CX diagnosis
Reviewing an existing service to find where it breaks down for real users, and defining what to fix.
Data-driven screen design & prototyping
Designing screens grounded in real usage data and logs, validated with working prototypes before a single line of production code.
Multilingual, multi-region service planning
The same discipline behind Bballi’s 10-language support, applied to other services.
Company information
- Company name
- 일오삼
- Representative
- 이윤재
- Business registration number
- 517-75-00525
- Address
- 경기도 파주시 경의로 1114, 4층 406호(야당동, 에펠타워)
- bballiapp@naver.com
For help using the app, bug reports, data corrections, or partnership and business inquiries, email bballiapp@naver.com or visit our /support page.