Digital sustainability for families across the UK

What the YoungPlanet delivery record supports
CoreLine rebuilt the YoungPlanet app for a UK platform that lets families pass on unused children's items free of charge. The engagement has run since 2020 and covers user research, UI design, a cross-platform mobile rebuild, and backend refactoring.
- 100,000+ users, as stated by YoungPlanet
- The user base is a client-reported platform figure covering the UK expansion, not a CoreLine measurement.
- React Native rebuild on iOS and Android
- The app was rebuilt cross-platform, with the backend refactored in Node.js and hosted on AWS.
- Research-led navigation and feature set
- The redesigned structure and the new engagement features came out of the user research run for this project.
Evidence basis: CoreLine's project delivery record, the technical scope documented in this public case study, and user-base figures provided by YoungPlanet.
Scope note: The user count is client-provided. No before-and-after stability, load-time, engagement, or retention figures are published for the relaunch; the client holds that analytics data.
UX RESEARCH
UI DESIGN
MOBILE DEVELOPMENT
BACKEND DEVELOPMENT
USER ANALYTICS
PRODUCT STRATEGY
A London-based mobile platform enabling parents to trade or donate unused children’s items - from toys to clothes - completely free of charge.
Transforming an app for conscious parenting and sustainable living
When YoungPlanet approached us in 2020, the app required a complete redesign to support its upcoming national launch. Originally built by another company, it struggled with UX challenges, performance issues, and scalability concerns.
Our mission was clear - preserve functionality, elevate the experience, and prepare the app for growth.

Balancing optimization with new features
The inherited codebase presented several technical limitations and design inconsistencies that hindered performance. At the same time, user engagement was declining due to complex navigation and limited features.
The challenge was to rebuild the app without disrupting existing users, ensuring smooth migration and improved usability.
To achieve this, we needed to:
- Understand user behavior and retention patterns.
- Improve app performance and responsiveness.
- Implement features that enhanced community interaction and product discovery.
Understanding users before redesigning for them
We began with a deep dive into user behavior analysis. Our goal was to strengthen loyalty among existing users while attracting new families nationwide.
Persona insights
YoungPlanet users were already well-defined: parents looking to donate, exchange, or receive items for their children. However, defining personas wasn’t enough - we needed real behavioral data to guide design decisions.
By integrating Amplitude Analytics, we gained valuable insight into conversion paths and drop-off points, helping us identify friction areas and optimize every interaction.

Simplifying, reorganizing, and humanizing the experience
The focus of the redesign was on clarity and usability. The main product screen - where users browse or request items - was cluttered and visually inconsistent.
We reorganized the layout, streamlined information hierarchy, and crafted a cleaner, more intuitive interface that allows parents to navigate seamlessly between browsing, posting, and chatting.
Key improvements:
- Simplified product details layout
- Improved accessibility and visual balance
- Streamlined interaction flows
Building engagement through smarter functionality
To meet users’ evolving needs, we introduced a set of new features designed around convenience and connection.
Sorting Filters
Users can now filter items by distance, ensuring easier coordination between families for local exchanges. This improvement alone significantly increased in-app engagement.
In-App Chat
To encourage direct communication, we integrated a built-in messaging system - allowing users to coordinate exchanges securely within the app.
Notification System
Using behavioral data, we developed personalized notifications that adapt to user intent - from donation reminders to nearby item alerts. This created a more meaningful, user-centered experience.
Fast, scalable, and optimized for growth
We rebuilt YoungPlanet using React Native for cross-platform performance across iOS and Android. The backend was refactored in Node.js, ensuring a faster and more reliable infrastructure.
All systems are hosted on Amazon Web Services (AWS) to maintain scalability and uptime as the user base grows.
From local initiative to nationwide impact
After months of design iteration, code refactoring, and feature expansion, YoungPlanet relaunched across the UK.
What the engagement delivered:
- A cross-platform rebuild in React Native, replacing the previous app on iOS and Android
- A refactored Node.js backend hosted on AWS
- A reorganized navigation and content structure, based on the user research run for this project
- New engagement features, shipped as part of the relaunch
YoungPlanet owns the app-store and product analytics for the relaunch. Stability, load-time, engagement, and retention are the outcomes the work was designed to improve, but this page publishes no measured before-and-after figures for them, so treat the delivery scope above — not an uplift — as the supported claim.

