
The Biogen Group, an international healthcare and biotechnology company, selected BeTomorrow following a call for tenders to take over the development of its Cleo application, a digital companion for people suffering from a serious neurological pathology : multiple sclerosis.
BeTomorrow collaborated with Cleo to take over the design and development of an application (super-app) dedicated to providing personalized support in the areas of health, nutrition and medical monitoring for patients.
BeTomorrow focused its expertise on the consulting and development of the existing mobile application, as well as on the takeover and reversibility of the project. Our specialists chose to adopt pay-as-you-go strategies to target an ambitious roadmap, while at the same time establishing a qualitative foundation for the code, enabling the project to be built in a stable and robust context.
Renewed confidence to meet tomorrow's healthcare challenges and improve the health of sclerosis patients.
Free access to reliable resources and wellness tips to monitor and improve daily life with MS.
Personalized advice modules on sleep, physical activity, mood and communication.


BeTomorrow chose React Native to optimize the performance of the native application. Optimizations have been made to the Rest API for optimal bandwidth and latency. There was also a focus on React Native Bridge for advanced features.
This project illustrates a major shift in the field of digital health, where apps are no longer limited to providing information, but are becoming genuine tools for long-term support.
With Cléo, the challenge was not simply to take over an existing system, but to rebuild a solid foundation capable of supporting an ambitious product roadmap within a demanding medical context. By combining technical expertise, a product-focused approach and rigorous UX standards, BeTomorrow helped transform the app into a health super-app centred on patients’ real needs.
Taking over the project, optimising the React Native stack and establishing a robust foundation have enabled us to secure future developments whilst guaranteeing performance and reliability. In an environment where quality, stability and confidentiality are critical, these structural choices directly determine the product’s value.
Beyond the technology, this project demonstrates that innovation in healthcare relies on the ability to create useful, personalised and accessible experiences. By combining design, data, agility and business expertise, Cléo is part of a new generation of solutions capable of providing long-term support to patients and addressing the healthcare challenges of tomorrow.

Developer Back-end
We took over Cleo's existing code, with significant optimizations. Switching from Kotlin to JavaScript was a formative experience for me. The JavaScript stack pushed us to explore technical solutions in greater depth, to implement functionalities comparable to those offered by Spring Boot.
Facing the challenges of everyday life with multiple sclerosis (MS) is a reality for many people. Thanks to Cleo, a free mobile application specially designed to accompany and support those living with MS, patients benefit from a wealth of information, support and practical tools to help overcome the difficulties encountered in their daily lives.

Director, Head of Engineering, Biogen HealthCare Solutions
We are looking for companies that have our DNA. BDH will not focus on the big market, but rather look at start-up type “markers”, short iterative cycles, lean mindset, agile methods. BeTomorrow has demonstrated its ability to enrich the value chain upstream (UX/UI) and downstream.