ExtraETF

ExtraETF is a comprehensive mobile platform for ETF and stock market analysis, providing investors with powerful tools for portfolio tracking and market research. The project focused on delivering a feature-rich native mobile experience with emphasis on real-time updates, seamless authentication, and premium subscription features.

Onboarding

News Page

Theme Page

Article

Equity Page

Equity Details

The Challenge

When Isarvest GmbH approached us to build ExtraETF, they had a clear vision: create a mobile application that would democratize ETF investing through powerful analytics and real-time market insights. The challenge was to deliver a sophisticated financial app that could handle complex data visualization, real-time price updates, and premium features while maintaining excellent performance and user experience across both iOS and Android platforms.

Our Approach

We chose Flutter as the foundation for mobile development, allowing us to build once and deploy to both platforms simultaneously. This decision proved crucial in meeting aggressive launch timelines while maintaining code quality and feature parity. Flutter's rich widget ecosystem and performance capabilities made it ideal for rendering complex financial charts and handling real-time data streams.

For real-time price updates, we implemented a Go-based WebSocket service that efficiently broadcasts live market data to both web and mobile clients. Go's concurrency model and lightweight goroutines made it the perfect choice for managing thousands of simultaneous WebSocket connections with minimal resource overhead.

Technical Wins

The Flutter implementation delivered immediate value. Development velocity increased dramatically as features were built once and deployed everywhere. The hot reload capability accelerated iteration cycles, and the single codebase reduced bug surface area by eliminating platform-specific inconsistencies.

The Go WebSocket service proved exceptionally efficient in production. Its ability to handle concurrent connections at scale meant that real-time price updates reached clients with minimal latency, even as the user base grew. The lightweight nature of Go kept server costs low while maintaining excellent performance.

Integration of native platform features—Apple and Google OAuth, push notifications, in-app purchases—was seamless through Flutter's plugin ecosystem. This allowed us to deliver platform-native experiences while maintaining the efficiency of cross-platform development.

Business Impact

The technology choices translated directly to business outcomes. Time-to-market was reduced by an estimated 40% compared to native development approaches. Maintenance overhead decreased as a single engineering team could manage the entire mobile stack.

The app successfully launched on both App Store and Google Play, achieving strong user retention through its smooth performance and real-time data capabilities. The subscription model, powered by robust in-app purchase integration, enabled sustainable revenue growth while the technical architecture scaled effortlessly with user acquisition.

Key Features

Push Notifications

Real-time market alerts and portfolio updates keep users informed about significant price movements, market news, and personalized investment insights. The notification system is built to handle high-frequency updates while maintaining battery efficiency and user preference controls.

Authentication & Social Login

Streamlined onboarding through Apple and Google OAuth integration provides users with secure, one-tap authentication. This reduces friction in the signup process and ensures account security through trusted identity providers.

Deep Linking

Universal links and app links enable seamless navigation from web content, email campaigns, and social media directly into specific screens within the app. Users can share specific ETFs, portfolios, or market analyses with others, creating a more connected user experience.

Interactive Charts

Advanced charting capabilities display market data with multiple timeframes, technical indicators, and comparison tools. The charts are optimized for mobile interaction with pinch-to-zoom, gesture controls, and responsive performance even with large datasets.

Theme Support

Full dark and light theme implementation adapts to user preferences and system settings, ensuring comfortable viewing in any lighting condition. The design system maintains visual consistency and readability across both themes.

Subscription Management

In-app purchase integration for premium features with seamless subscription management through Apple App Store and Google Play Store. The system handles trial periods, subscription tiers, and restoration across devices.