NineCoach

Premium Language Coaching without the premium price tag

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Inspiration

We’ve always believed that communication is the ultimate superpower. The way you speak can open doors, build trust, and create opportunities across cultures and careers. Yet most people never get the chance to truly train their voice. Traditional language learning apps focus on grammar and vocabulary — but real impact comes from confidence, clarity, and pronunciation.

That’s where the idea for NineCoach was born: to give everyone access to a world-class voice coach, right in their pocket.

What it does

NineCoach is an AI-powered speaking coach that helps you sound more fluent, confident, and natural in English (and soon, other languages). It’s like having a $500/hour personal coach available 24/7.

  • 🎤 Onboarding Assessment: Get a personalized score of your speaking skills.
  • 🧠 Skill Loops: Daily tailored exercises that adapt to your level and goals.
  • 🔄 Real-Time Feedback: Practice conversations with AI that listens, corrects, and encourages.
  • 📈 Progress Tracking: Watch your pronunciation, clarity, and fluency improve week by week.
  • 🌍 Scenario Training: Rehearse job interviews, sales calls, or presentations in a safe environment before the real thing.

How we built it

NineCoach was built with a mobile-first architecture in Flutter, powered by cutting-edge AI models. We integrated:

  • OpenAI’s real-time speech APIs for natural, back-and-forth conversations.
  • Whisper for lightning-fast, accurate speech transcription.
  • A custom Skill Loop Engine to personalize lessons and keep users engaged.
  • Firebase for a reliable and scalable backend.

The design is intentionally premium and minimal — because we want every session to feel like sitting down with your own high-end coach.

Challenges we ran into

Building NineCoach meant solving tough problems:

  • Delivering real-time audio feedback with near-zero lag.
  • Keeping AI conversations natural and encouraging rather than robotic.
  • Designing lessons that feel human, not mechanical drills.
  • Balancing cost efficiency with high-quality AI models.

We overcame these by experimenting with multiple model providers, designing a personalization layer that adapts on the fly, and obsessing over user testing to make sure the experience is both effective and enjoyable.

Accomplishments we’re proud of

  • Launched a working iOS alpha in record time.
  • Built an app that early testers describe as “more motivating than a human tutor.”
  • Created a fun, shareable progress system that keeps users coming back.

What’s next

We’re just getting started. Coming soon:

  • More languages beyond English.
  • Specialized modules for business, travel, and everyday conversation.
  • Enterprise version for teams that want sharper, more confident communication.

Our mission is bold: help millions of people worldwide unlock their full voice and potential.

Learnings

We learned that building something truly helpful with AI is less about the technology itself and more about how you design the experience. A coach isn’t just a feedback loop — it’s encouragement, accountability, and progress. NineCoach is our attempt to bring all of that together in one place.

Built With

  • claude-code
  • flutter
  • gpt4-realtime
  • supabase
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