Johns Hopkins

Designing and Building a Health and Wellness Mobile App

Project Type
Mobile App
React native




Aws cognito


Aws amplify


Johns Hopkins School of Medicine was chosen by the American Heart Association (AHA) to investigate the effects of time-restricted feeding on obesity and cardiometabolic outcomes. The study administrators needed to develop a mobile app, Daily24, that would be easy and engaging for the 2,000+ study participants to enter their daily meal and sleep data for six months. The Gnar Company was hired to design and build the Daily24 mobile app for Johns Hopkins.

Discovery and Design

The Hopkins research team and The Gnar Company kicked off the work with a Discovery and Design project to define the user personas, user journeys, app name and logo, as well as key app features. In addition, a user feedback council was created to confirm user personas and facilitate app user feedback. The Discovery workshops were followed by the mobile app product flows and click demo. The click demo was reviewed with the team and user feedback council to solicit input. The designs were revised and an MVP was built with the core data collection features.


Gnar utilized multiple third-party services in Daily24, including AWS Cognito for user management and Amplify for cloud services integrations.

Mobile App

The Gnar Company built Daily24 with React Native, and launched apps in both the Apple App Store and Google Play Store. Daily24 enables users to log when they eat, drink, and sleep, as well as estimate meal size. The app also includes gamification aspects (such as trophies and and a leaderboard) to encourage daily usage for the AHA study participants.