Runtastic Libra for Android

The companion app of Runtastic’s smart scale helps people keep track of their weight and body composition, setting and achieving healthy goals.




Dec 2014–Feb 2015

Why it was needed

Many users left behind

Runtastic Libra is a smart scale that analyses body metrics — including weight, body fat and water percentage — and can transfer data to a smartphone using Bluetooth. The company had launched the scale in the Fall 2013, but one year later the companion app was still only available for iOS. Customers were often writing to the support team and on social media, asking when the Android app would finally be released. Note: after Runtastic was aquired by Adidas in August 2015, the company stopped selling hardware and in September 2019 it discontinued the Libra app.

The Android robot in front of the Libra scale
The Android robot shows you the Runtastic Libra scale. Photo: Jakob Lehner.
My role and the team

Fantastic team work

I was the lead designer of the Android app, discussing the screens with the designer who had worked on the iOS version, and working closely with the developers who were implementing the UI. The synergy with the project manager and the developers was great, and led to a great human and professional esteem among the members of the team.

The Android robot in front of the Libra scale
Opening a measurement from the weight history.
Design process

Working with user insights

The iOS design was taken as a starting point for the Android app, to offer a consistent experience across the platforms. Rather than just reskinning the iOS app, and improving from what we learned on the Sleep Better project, we gathered feedback from existing users to see how we could improve the experience. We identified and interviewed some people from other teams in the company who were using the scale with the iOS app, as well as some external users, with the help of the Support team.

Two Android phones showing two screens of Libra
The home screen of the app (left), and the screen that is displayed while a measurement is in progress (right).

While a few users complained about Bluetooth connectivity issues with the scale, the general feedback about the UX was positive. However, the graph showing the history of the measurements was obscure to many. The redesign of the legend at the right of the graph, with clear units of measurements for both weight and body fat percentage, led to a massive improvement in our usability testing sessions.

The weight history graph on iOS and Android. the Android version adds the units of measurement.
A comparison of the weight history graph in the old iOS design (left) and Android (right), with the redesigned legend at the right of the graph.

Some power users also complained it was hard to keep track of changes in their body composition. Opening one measurement at a time — and remembering each value — was the only way to do so. To make this comparison easier, we decided to provide the users with a full body composition graph showing the percentages of each value (body fat, muscles, tissue, bones) as they change through time.

In addition to this, when users set goals in the app (like “lose 4 kg by the 1st of June”) they were not able to see how they were progressing toward that goal in the weight history graph. With the addition of a simple dashed line, we made that very easy to understand at a glance.

The full screen body composition graph, and the weight history screen, which includes a graph of the measurements on the top and a list at on the bottom
The full body composition graph (left) satisfies the requests of power users. The dashed line (right) makes it easy to see the progress toward your goal.

Delighted users and a close-knit team

The Runtastic community was really happy to finally be able to use the Libra scale with Android devices. The interface is one of the most praised aspects of the app in the reviews in the Store. In addition to this, the great team work on this project made the whole team look forward to working together again in our next project.

Two 5-stars reviews from the Play Store