Greenr

The most innovative and intuitive carbon footprint tracker. Made with Flutter.

  • 12,800+

    tonnes of CO₂e avoided

  • 5,600+

    cars taken off the road

  • 90

    countries with Greenr users

Turning carbon footprint tracking into a rewarding experience

  • Challenge

    Creating a new kind of climate engagement platform for users and enterprises

    When Greenr approached us, they had a bold vision: to make carbon footprint tracking intuitive, social, and rewarding for individuals and, later, businesses.

    Initially, the app was designed for individual users, particularly millennials and Gen Z, to help them track their carbon emissions, offset them, and adopt more sustainable behaviors.

    However, Greenr’s long-term vision wasn’t just to serve consumers, but also to provide a solution for businesses and organizations looking to achieve net-zero goals.

    To get started, the Greenr team needed a trusted partner to help them:

    • Quickly build an MVP mobile app to meet government funding deadlines without exceeding strict budgets.
    • Deliver a smooth, gamified user experience that would appeal to a young, tech-savvy audience.
    • Build a scalable foundation that could expand into B2B services for companies that need to track and report their own carbon emissions.

    Greenr wasn’t just launching another sustainability app – they were creating a new kind of climate engagement platform. The technical execution had to be flawless, fast, and flexible enough to evolve with their ambitious roadmap.

  • Solution

    Three stages of growth: From individual tracker to corporate climate companion

    First iteration
    In its first iteration, Greenr focused on the individual user experience. This included developing a gamified carbon tracking app that enabled users to easily track their daily activities (e.g., meals, transportation), measure their carbon footprint, and receive instant feedback on ways to reduce or offset it.

    Key features included:

    • A carbon footprint quiz to assess daily activities and lifestyle choices.
    • A rewards system where users could earn badges, crowns, and points for sustainable behaviors.
    • Social features to engage users, track their progress against peers, and encourage participation through friendly competition.

    Second iteration

    As Greenr’s initial user base grew, the need for enterprise-level solutions became apparent. In the second iteration, Greenr expanded its platform to meet the needs of organizations looking for carbon tracking and employee engagement tools.

    This included:

    • Introducing employee engagement tools and the ability to track company-wide carbon footprints.
    • A corporate dashboard where companies could manage and report on their emissions while engaging employees in sustainability efforts.
    • New features such as supply chain management to help companies switch to more sustainable suppliers and offset emissions.

    Third iteration

    By the third iteration, Greenr’s platform had become a full-fledged climate companion for both individual users and businesses.

    This version featured:

    • Comprehensive data and customized action plans for organizations pursuing net-zero goals.
    • The employee engagement tool was expanded to include in-app challenges, progress tracking, and performance benchmarking.
    • A corporate version that enabled companies to report emissions and make more sustainable decisions, such as switching suppliers and purchasing carbon offsets.
  • Results

    Empowering individuals and organizations to take action against climate change

    Successful B2C & B2B transition: Greenr smoothly transitioned from a consumer-focused app to a platform that supports both individuals and businesses, expanding its user base and creating new revenue streams.

    Engaged user base: Gamification proved highly effective, driving consistent engagement and making carbon tracking fun for Millennials and Gen Z. With rewards, challenges, and social interaction, Greenr successfully turned sustainability into a daily habit.

    Business growth: For businesses, Greenr’s employee engagement tools and carbon data tracking were key drivers of success. Companies were able to seamlessly integrate sustainability into their operations, track emissions, and work toward net-zero goals.

    Greenr’s real-world environmental impact:

    • 12,800+ tonnes of CO₂e avoided
    • The equivalent of 565,000 trees growing for one year
    • Over 5,600 cars taken off the road
    • Users across 90 countries and counting

    Future-proof platform: Built on a flexible tech stack, we prepared the app to support upcoming features like AI-powered food tracking and advanced reporting without rebuilding.

  • Download the app

Key features

  • Walkthrough

    A friendly, visual onboarding experience guides users through the app, highlighting key features and how to use them.

  • Quiz

    Users take a short quiz on lifestyle factors such as diet, commuting and shopping habits to assess their carbon footprint.

  • Quiz results

    The app provides a detailed breakdown of users' carbon impact, compares their results to peers, and provides illustrative examples of their annual carbon footprint.

  • Track activities

    Users log activities such as food consumption and travel methods. The app calculates the carbon footprint for each action and displays it in an easy-to-understand format.

  • Statistics section

    A central hub where users can track their carbon footprint, monitor progress toward reducing emissions, and view key statistics such as CO2e saved.

  • Making pledges

    Users commit to eco-friendly habits by choosing from over 200 pledges in different categories (home, food, travel, etc.), helping to reduce their carbon footprint.

  • Claiming badges

    After completing pledges, users earn badges to showcase their achievements and motivate continued progress.

  • Challenges

    Users can participate in challenges using unique organizational codes and compete with peers to reduce carbon emissions.

  • Levels

    Climbing levels through challenges and pledges unlocks access to more ambitious goals, further incentivizing green behavior.

  • Carbon offsetting

    Users can support carbon offset projects to neutralize their emissions and contribute to global sustainability efforts.

  • Strava integration

    Link to your Strava account to automatically track activities like biking and running, while tracking how much CO2 you avoid.

  • Partner's offers

    Exclusive deals and promotions from Greenr's partner brands help users make more sustainable purchases.

  • Log in

    Sign up or log in easily with email, Google account, or Apple ID (iOS) for seamless access.

  • Giving feedback

    Users can share feedback or report issues directly in the app to help improve the experience.

How we did it

  • Mobile app

    • Framework

      Flutter

    • Language

      Dart

    • Architecture

      BLoC

    • Networking

      Dio

    • Continuous Integration

      Bitrise

    • Testing

      Alice

    • App Integration

      Strava

    • Dependency Injection

      getIt

    The Greenr mobile app was built using Flutter, allowing us to deliver a high-performance, cross-platform experience from a single code base.

    To maintain a clean and maintainable architecture, we used the BLoC pattern, which separates the business logic from the UI layer. For payments, we integrated the Stripe API to ensure a seamless and secure checkout flow.

    One of the more complex elements of the app-the main dashboard-featured multiple nested scrolling views. To ensure smooth performance and intuitive navigation, we designed and implemented a custom solution tailored to this layout.

    Development began before Dart introduced null-security, which later required us to refactor and upgrade the codebase to meet modern Flutter standards.

    We also worked closely with the client’s in-house developers, successfully coordinating the code architecture and integrating them into our development process for an efficient and collaborative workflow.

  • Web app

    • Web framework

      React

    • Language

      TypeScript

    • Framework

      Create React App

    • UI

      Material UI

    • Hosting

      Firebase hosting

    • Architecture

      modular

    • Networking

      ky

    • Authentication

      Firebase

    For the web app, we built a single-page application using Create React App, which allowed us to start development quickly with all the modern essentials – routing, hooks, layouts, and theming – already in place.

    The frontend was developed in TypeScript to improve code reliability and catch bugs early in the development process.

    To ensure visual consistency and speed deployment, we built the UI using Material UI, leveraging a premium theme that perfectly matched the designer’s vision. This approach significantly reduced the time and effort required to build custom components from scratch.

  • Backend

    • API type

      REST

    • Language

      TypeScript

    • Framework

      NestJS

    • Database

      PostgreSQL, TypeORM

    • Application Platform

      Google App Engine

    • Authentication

      Firebase

    • End-to-end tests

      Jest

    • Continuous Integration

      Semaphore

    We built the backend from the ground up using the NestJS framework and designed a REST API to handle multiple user types and complex data requirements.

    Key features include:

    • Managing users’ carbon events and activity logs
    • Powering personalized dashboards for individuals
    • Aggregating and displaying emissions data for partner organizations

    To ensure fast and secure access, we integrated Firebase authentication, offloading auth flows while maintaining robust user role control. The system supports three distinct user types: individual application users, business partners, and Greenr super administrators – each with access to only the data and tools they need.

    To optimize performance, especially when handling complex queries such as enterprise-level carbon spending, we introduced denormalized read-only SQL tables. This dramatically improved response times and ensured a smooth user experience at scale.

  • Design

    • Wireframes

      Figma

    • Interactive prototypes

      Figma

    • UI Designs

      Figma

    • Design System

      Material Design 2 (Figma)

    Our collaboration with Greenr began with a product discovery workshop, where we gained a deep understanding of the project’s goals and user needs. During this phase:

    • We reviewed and analyzed the client’s initial wireframes.
    • We mapped key user flows and suggested improvements to enhance intuitiveness and usability.
    • We conducted a competitive analysis, looking at similar apps on the market – such as MyFitnessPal – for inspiration and differentiation.

    This process helped us define a clear and unified product vision that balanced business goals with real-world user expectations.

    Next, we moved into the ideation phase, where we translated early insights into tangible visual and functional concepts:

    • We created a moodboard to establish the visual tone and aesthetic direction of the app.
    • We designed a clickable, low-fidelity prototype and refined screen layouts and user flows.
    • Key requirements were gathered during ideation sessions with the client’s product owner.
    • We also produced the first high-fidelity screens, which set the visual style for the rest of the app.

    By the end of this phase, the entire team had a common understanding of how Greenr should look, feel, and function.

    After refining the concepts and prototypes, we moved on to finalizing the user interface with implementation in mind.

    • The UI was built using the Material Design library, in line with the decision to use Flutter as the core front-end technology.
    • Our designers worked closely with the developers to ensure a smooth handoff, cost-effective implementation, and minimal technical rework.
    • Custom illustrations were added to enhance the visual identity and support the brand’s mission of building an eco-conscious community.

    This approach enabled us to seamlessly transition from design to development, laying a strong foundation for the build phase.

  • Quality assurance

    • Test management

      Jira, Xray

    • Device farm

      Browserstack and STF (Smartphone Test Farm)

    • Crash reporting

      Crashlytics

    • API testing

      Postman

    • Http requests debugging

      Alice

    • Performance Monitoring

      Firebase

    To deliver a stable and high-performing product, we have established a comprehensive QA strategy that combines real device testing, intelligent tools, and network simulations.

    Test environment

    We ensured broad device and platform coverage by testing on:

    • A variety of physical devices with different OS versions
    • BrowserStack and STF (Smartphone Test Farm) to simulate different configurations
    • Multiple network types (3G, 4G, Wi-Fi) to validate performance in real-world conditions
    • A robust test data setup to simulate different usage scenarios and edge cases

    Test management & tools

    Our QA process included manual testing supported by:

    • JIRA and Xray for test planning, defect tracking, and reporting
    • Postman for API testing
    • Crashlytics and Alice for crash and log monitoring
    • Firebase Performance Monitoring to identify and resolve performance bottlenecks

    This robust setup helped us ensure that the Greenr app met the highest standards of functionality, usability, and reliability for both consumer and business use cases.

How it works

Why our clients choose us

We couldn't have made a better choice! Thanks to Droids On Roids' skilled team, expertise in Flutter and efficient processes, we stayed on budget and met deadlines without compromising quality. They're honest with their estimates and a fun group to work with!

Greenr is a climate app that tracks your carbon footprints. Get rewarded for every positive change that you make in your lifestyle.

Gabrielle Bourret-Sicotte

Greenr Co-Founder & CEO

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