2nd Place — ZeroOne Hackathon 2026

Build Habits.
Together.

A social accountability app that turns group habits into shared progress. Compete with friends, maintain streaks, and actually follow through.

Try Live Demo View Source
OnlyFriends Home Screen
Home screen showing communities and streaks
Home · Communities
Friends leaderboard
Friends · Leaderboard
Profile with achievements
Profile · Achievements
Everything you need.
No bloat. No ads. Just the mechanics that actually drive behavior change.

Private Communities

Create focused spaces for specific goals — fitness, reading, coding. Invite only the people who matter.

Shared Task Lists

Everyone in the group sees the same daily/weekly tasks. One group, one mission, zero ambiguity.

Duolingo-Style Streaks

Maintain your daily streak. The longer it runs, the harder it hurts to break. Psychological commitment at scale.

Points & Leaderboards

Earn points for every task you complete. Compete in real-time rankings. Gamification that actually works.

Achievement Badges

Unlock milestones like "Early Bird", "Streak Master", and "Century Club". Tangible progress markers.

Smart Notifications

Get notified when friends complete tasks, overtake you on the board, or when your streak is at risk.

The Origin Story
Before any code was written, there was a WhatsApp group.

Five friends made a simple pact: share what you did today. Exercise logs with sweaty selfies. Book summaries. Coding streaks. Every update had proof attached.

No algorithm, no suggested posts, no ads. Just five people holding each other accountable. And it worked for over a year.

Some of us read 20+ books. Others hit fitness goals we'd been putting off for years. That emotional loop — part competition, part community — is what we bottled into Only Friends.

"Missing an update felt wrong. Seeing your friends hit their goals made you want to hit yours."
— The founding principle of Only Friends
Built on Research.
This isn't a random habit app. Every feature is grounded in behavioral psychology.
10%
Goal set alone
(willpower only)
65%
Goal committed
to someone
95%
Goal with specific
accountability check-ins
3×
More consistency
when peers are watching

Social Proof

When you see friends completing tasks, it triggers motivation. Each completed task is a nudge. (Robert Cialdini, Influence)

Loss Aversion

Breaking a 30-day streak hurts more than skipping a workout. Duolingo proved streaks drive 3× more daily engagement.

Variable Rewards

Points, badges, and leaderboard shifts create the same dopamine loop that keeps you coming back. (Nir Eyal, Hooked)

The Köhler Effect

People work harder in groups than alone, especially when they know their effort is visible. Research-proven since 1926.

The Infinite Loop

You complete a task → Friend sees it → Friend feels motivated → Friend completes a task → You see it → ∞ Repeat
Try It Live.

Run the app locally with npx expo start --web inside apps/mobile then open on port 8081.

Clone the repo, install dependencies, and run npx expo start --web to try the full app in your browser.

Get Started on GitHub
The Builders
Built in 48 hours by three friends who lived the accountability experiment firsthand.

Mohammed Ishaaq

D Karthik Raj

Ullas M