Bayer - Wonder-app

Wonder app supports the users of hormonal coil – also known as intrauterine system or IUS – before and after installing the device.

Our job was to design and build a service that offers precise information about IUS and lets the users monitor their well-being while using it.

Service Design

We interviewed both medical professionals and current IUS users to find out what the most common needs, questions and issues are – and what the application's role could be in terms of offering support.


    We created several outlooks for the app that were tested with the end users, medical personnel and people at Bayer. This work eventually resulted in a concept that we began developing further. During development, Figma proved to be an invaluable tool that helped us get quick answers to UX-related questions.

Software Development

    The app was built using the React Native framework. Since the app includes a hefty amount of content that requires frequent updates, we opted for using Contentful – a tool that lets the client change the text content quickly by themselves. Both technologies were selected based on Bayer's requirements: they wanted to move fast but not sacrifice neither quality or scalability.

Continuous Improvement

    In addition to anonymised analytics, we defined the key metrics for the app in co-operation with Bayer.

Wonder - monitoring one's condition

Monitoring one's condition

After starting to use the IUS, the user can use the app to mark down the heavier and lighter bleeding days and how they feel.

The summary view makes it easy to view these changes in the context of longer time periods. Naturally, this information may also help the doctors in case of questions or issues.

Wonder App iPhone
Bayer - Smart IUS guide

Smart IUS guide

The IUS guide included in the application offers information about the device's effects on birth control and menstrual cycle.

The user can also use the app to prepare for the installation. The guide explains how the installation procedure is performed, how it feels like, which effects are normal and in what kind of situations one should contact their doctor.

Moreover, the app features an FAQ section concerning the IUS as a birth control method, hormone function, periods, pregnancy and breastfeeding.

Content Upload Web
App Content iPhone
Content Upload

Fast content updates

It was crucial that Bayer could easily update the text content of the app. For this reason, we ended up using Contentful as our content management tool. With it, the copy changes are immediately visible in the app. From the content producers' perspective, this makes it possible to do quick changes without long delays.

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