CheckMotion: AI Sports Coaching for Every Athlete

The Spark: From Passion to Purpose

As a lifelong sports enthusiast who spends every free moment either on the bike, at the gym, or exploring new athletic challenges, I've always been frustrated by a glaring gap in the fitness tech world. While professional athletes have access to biomechanics experts, movement coaches, and detailed performance analysis, hobby athletes like myself were left with generic YouTube tutorials and one-size-fits-all training plans.

The question that kept me up at night was simple: Why shouldn't every athlete have access to personalized coaching?

The Journey Begins: PedalPro

My first attempt to solve this problem was PedalPro.io – an AI-powered bike fitting solution that uses computer vision to analyze cycling posture and provide professional-grade bike fit recommendations. What started as a personal project to optimize my own cycling performance quickly gained traction in the cycling community.

The response was overwhelming. Cyclists from around the world were uploading their pictures, getting insights that previously required expensive visits to bike fitting specialists. This validation proved my hypothesis: There's massive demand for accessible AI coaching in sports.

The Evolution: CheckMotion is Born

For the RevenueCat Shipaton, I decided to take everything I learned from PedalPro and go bigger. CheckMotion represents the next evolution – a universal AI sports coaching platform that brings professional-grade movement analysis to every athlete, regardless of their sport or skill level.

The vision was ambitious: Create an app that could analyze any athletic movement, provide biomechanical feedback, and deliver personalized coaching insights powered by the latest in AI technology.

Building the Technology Stack

CheckMotion leverages cutting-edge technologies to create a truly adaptive sports coaching experience:

1. Kotlin Multiplatform & Compose Multiplatform: By building the app and backend with Kotlin Multiplatform and Compose Multiplatform, I write the UI once and deploy seamlessly to both Android and iOS. This unified codebase ensures consistent user experience across platforms while dramatically reducing development time.

2. AI-Driven Adaptive UI: This is where it gets really innovative – the UI itself is powered by AI. Using LangChain to orchestrate different AI models alongside custom-trained models, the interface dynamically adapts based on your selected sport. The UI elements you see aren't hardcoded; they're intelligently generated based on what the AI determines is most relevant for your specific sport use case. A swimmer sees different analysis tools than a weightlifter, all determined in real-time by AI.

3. Intelligent Backend Services: The backend leverages multiple AI services working in concert to:

   • Provide deep biomechanical insights from your movement videos
   • Enable natural conversations about your analysis through an integrated chat interface
   • Rate and track your performance over time with AI-powered scoring
   • Generate personalized improvement recommendations based on your unique movement patterns

This architecture means CheckMotion isn't just another fitness app with AI bolted on – it's fundamentally built on AI from the ground up, creating an experience that adapts and evolves with each user.

The Challenges: Turning Vision into Reality

Building CheckMotion presented unique challenges:

• Multi-Sport Complexity: Unlike PedalPro's cycling focus, supporting multiple sports meant creating flexible architecture that could adapt to vastly different movement patterns

• Fast Processing: Ensuring smooth, fast analysis on mobile devices while maintaining accuracy required extensive optimization

• User Experience: Making complex biomechanical feedback accessible to everyday athletes without dumbing down the insights

• Monetization Strategy: Implementing RevenueCat to create a sustainable subscription model that provides value while keeping the app accessible

What's Next

CheckMotion isn't just an app – it's the beginning of a movement to make professional-grade sports coaching accessible to everyone. By combining custom AI models with the interpretive power of LLMs, we're creating a future where every athlete, regardless of budget or location, can train like a pro.

The RevenueCat Shipaton has given me the perfect platform to showcase how AI can transform the way we approach sports and fitness. My next step is now to finetune my custom models and take the results to the next level!

Built With

• compose
• docker
• kotlin
• kotlin-multiplatform
• ktor
• kubernetes