EFFEFF Co., Ltd · Software Studio

Driven by Efficiency,
Proven by Effect.

Every problem is solvable — it just takes will and time.

We move that possibility forward with efficiency and prove it with results.
We find the market's real problems, ideate boldly and freely,
validate coldly and rigorously — and build things that genuinely get used.

View ProductsContact Us
Founder portrait

CEO / Founder

Han Gyeol Ryu

유한결

Leadership / CEO

Turning the value the world needs into effective systems.

Through an engineering career rooted in Silicon Valley, I've experienced firsthand that technology is the most powerful means of solving the essential problems of a business. To me, development goes beyond simply shipping features — it's a process of strategic engineering design that crafts business logic precisely and proves it in numbers.

I favor data-driven agile execution over vague hypotheses. I rapidly turn ideas into reality to precisely target the market's pain points, and I maximize the probability of business success by refining the product with real feedback as fuel. As CEO of EFFEFF Corp, I'm simultaneously building solutions that fill the market's gaps across security, location-based services, commerce, and more — continuing real, hands-on market validation.

We don't just talk about possibilities. By building efficient systems, we prove the real-world effect on the business and show — through results — how technology contributes to the world.

Han Gyeol Ryu, CEO of EFFEFF

Apps I contribute to

SOWANT

SOWANT

iOS & Android

Cool as a Cucumber Inc

A taste wishlist app — meet niche brands hand-picked by editors, save anything from any shop with a single link, get restock and sale alerts before items vanish, and follow people whose taste matches yours. Co-founded and serving as CTO, leading app planning, technical architecture, and service launch.

Chambang

Chambang

iOS & Android

Algoboni

An easy, fast way for small business owners to build a loyal customer base — one phone tap at the counter logs a visit, unlocking store, neighborhood, and brand-partner perks, plus 'Chamsae' word-of-mouth referrals. Alongside 'Chambang Biz' for owners. Contributed as a builder, handling product design and development.

TITA

TITA

iOS & Android

EFFEFF Co., Ltd

An AI-powered, safe friend-matching community for people 45+. One daily question sharpens your peer recommendations, and small offline tea meetups turn them into real meetings. Patent-pending security technology and accessibility-first design — built, developed, and operated in-house.

Kkaejoh

Kkaejoh

iOS & Android

EFFEFF Co., Ltd

Korea's model restaurants and Kkaejoh-certified clean restrooms on one map — 30,000+ restaurants and 63,000+ public restrooms across all 17 regions, in-unit vs. shared restroom labels, an emergency nearest-three finder, and unannounced three-tier cleanliness certification. Designed, developed, and deployed in-house.

Dishtill

Dishtill

Web · Pilot

EFFEFF Co., Ltd

A food–drink pairing service that recommends the drink that best suits each dish by taste. Drink-list diagnosis, a QR menu in Korean, English, Japanese and Chinese, and a monthly report on how guests browse the menu help restaurants sell more drinks. Pairing engine, owner console and guest web are designed, built and run in-house.

Gaeun

Gaeun

Coming soon

EFFEFF Co., Ltd · iOS TestFlight private beta

Pick the workout you just finished and what's next, and it sets today's sauna temperature, time per set, and when to take the cold plunge. The recovery score is shown with the arithmetic that produced it rather than hidden, and alcohol, fever, or a heart condition stops the numbers before they appear. Reads Apple Watch sleep and HRV while raw health data never leaves the device.

Our Product · Core Identity

A patent-built
AI safe friend-matching platform
TITA

"Meet friends who fit your vibe, slowly — a reassuring afternoon teatime."

01. The Problem & Vision

Connection after the empty nest: The void left after the kids move on, and the risks of voice phishing, romance scams, and investment fraud. We design for 'reassurance' rather than loneliness, and for 'friends who fit your vibe' rather than dating.

Slowly, safely: AI recommends peers nearby based on shared interests every day, while patent-pending security technology blocks risks. We add real friends to your second chapter, starting at 45+.

02. Key Pillars

AI Safety Shield (Patent-Backed Security)

Application No. 10-2026-0024079 · integrated 4-layer safety filing PA260003 (expedited review in progress)

  • 'Cognitive Fingerprint' technology detects voice phishing and scams in real time.
  • It analyzes each user's unique touch patterns and response speed to instantly block abnormal access.
  • An L1·L2 layered AI engine precisely filters even subtle, context-based fraud.
  • Paste a suspicious message and the AI instantly points out its intent and scam patterns — the 'Let me check this message' feature.

Vibe-Matched Friends (AI Matching)

  • AI recommends peers who fit your vibe every day, based on shared interests and your neighborhood.
  • We start by connecting you with peers within ~10 years of your age, at a distance where you can actually meet.
  • Friendship-first, not dating — AI points out how the two of you are likely to click.
  • One short question a day ('GyeolQ') sharpens your recommendations, and every profile shows how closely you match as a percentage.
  • Even before signing up, an 18-question 'vibe type' test shows you your vibe in about three minutes.

Offline Teatime (Offline Tea Meetups)

  • Small gatherings of three or four, hosted by our team — sign up after seeing the date, neighborhood, fee, and seats left.
  • Everyone signed up for the same meetup gets a shared chat room, so you can say hello before you arrive.
  • No meetup that suits you? Tell us when and where, and we'll open that seat.
  • In 'Stories', read pieces from TITA and fellow members — and write your own.

4-Layer Safety Net (Multi-Layer Safety)

  • Only members verified through NICE identity verification can join.
  • AI detects fraudulent message patterns 24/7, and incoming reports are auto-triaged and reviewed by AI for fast handling.
  • Adaptive design automatically adjusts the screen for eyesight and hand tremors.
TITA app icon

TITA App

Vibe-matched friends, 45 and up

TITA app home screenTITA app browse screen
Patent-BackedApplication No. 10-2026-0024079 · PA260003 expedited

Cognitive Fingerprint · Layered AI Security

Cognitive Fingerprint and an L1·L2 AI engine detect and block voice phishing, scams, and context-based fraud in real time. The integrated 4-layer safety patent is under expedited review, with four more filings in preparation.

Blocks abnormal access via touch & response patterns
Precise context filtering
Reassuring peer-to-peer community protection

Our Product · Core Identity

Clean restaurants & restrooms
on one map
Kkaejoh

"The easiest way to find a clean restroom."

Model restaurants
30,000+
Public restrooms
63,000+
All 17 regions
Nationwide

01. The Problem & Vision

An information gap: There are plenty of restrooms, but no way to tell which ones are clean. Public data is outdated, and a map that only drops a pin tells you nothing about what's waiting behind the door.

Trust we build together: Government-designated model restaurants come from public certification data, and Kkaejoh visits and grades the restrooms itself. Users flag the dirty ones in a single tap, which keeps the data honest — and anyone can browse the whole map without logging in.

02. Key Pillars

Place Search & Emergency (Naver Maps & Emergency)

  • Integrated with the Naver Maps API to search by real place names — buildings, brands, and more — and move around the map.
  • 30,000+ model restaurants and 63,000+ public restrooms across all 17 regions of Korea, on a single map.
  • Switch the restrooms ↔ restaurants layer with one tap, and filter restaurants by cuisine — Korean, BBQ, Japanese, snacks, cafés.
  • Five filters narrow it down: clean only, gender-separated, 24h, wheelchair access, and exclude old buildings.
  • Emergency mode surfaces the three nearest restrooms as cards, with turn-by-turn navigation and native sharing.
  • Browse instantly without logging in; pan the map and restrooms in that area load in real time.

Facilities & Restroom Details (Facilities & Details)

  • Structures detailed information across 18 facility categories (baby/family, hygiene, basic amenities, comfort).
  • Estimates whether a venue's restroom is in-unit or shared in the building from its size, then confirms it with user reports.
  • Supports Korean, English, Japanese, and Chinese.

Crowd Verification & Reports (Trust & Reports)

  • Reliability updates automatically as user reports accumulate — a weighted 1–5 trust score from confirm/deny ratios, shown as Confirmed, Needs check, or Denied with the numbers behind it.
  • Flag a dirty restroom in one tap; once reports pile up, a warning appears on the map.

Venue Certification (Certification Programme)

Now accepting applications
  • Paper, soap, working fixtures and no odor are only the gate — on top of that we grade how clean it actually is and how well it's kept.
  • A venue applies, then we visit unannounced to check floors, sinks and toilets alongside cleaning cadence, ventilation, and consistency.
  • Passing venues get a three-tier rating (★–★★★), and user dirty-reports keep it honest afterwards.
Kkaejoh app icon

Kkaejoh App

A map of only the clean ones

Kkaejoh app preview 1Kkaejoh app preview 2
Data quality

AI Filtering · Report · Reward Loop

Filters out inappropriate or duplicate information, and builds trust for contributors and users alike through reports and rewards.

AI-based content & pattern filtering
Auto-hide rules when reports accumulate
Point rewards to maintain quality

Intellectual Property

Patents & Technology

We put user safety first with our own patent-pending security technology. Through a financial-grade security architecture and an AI-based real-time threat detection system, we protect you from scams and phishing.

Patent Pending

Senior-Specific Social Platform System

시니어 특화 소셜 플랫폼 시스템

An integrated system that enhances the security and trustworthiness of user interactions on online social platforms for senior users. It combines user identification, content exposure control, AI-based anomaly detection, and hybrid matching technology.

Filing Date

February 6, 2026

Status

Filed

1

AI-Based Connection Recommendation

2

Real-Time Scam Detection & Blocking

3

Automatic Accessibility Optimization

4

Specialized Social Platform System

Contact

Let's shape the next outcome together.

Feel free to reach out about project consulting, collaboration proposals, or technical inquiries.

ceo@effeffcorp.com
+82 10-5647-1196
Seoul, Republic of Korea