App Design

Doppel is a revolutionary wearable that works with your body so it can actually alter your mood to make you more alert or feel relaxed.  It is worn on the inside of your wrist and is synced with an accompanying app which controls it. 

The device emits a vibration that feels like a heartbeat. Your brain responds naturally to the rhythm – similar to listening to upbeat or, alternatively, calming music.

The Problem

The original Doppel app was created for iPhones. It wasn’t a user-centric design and with production of the device imminent, the company approached me to review and redesign an enhanced app interface.

It was key that the app was simple to use for all user types and catered for all their requirements.

The Process

I began by conducting research on doppel’s intended user-base, in order to understand what their main goals was. To obtain insights, 
I carried out a series of informal testing sessions, and conducted internal interviews with the key stakeholders within the company. Further to this I analysed the current interface to define fundamental issues with it, and began to detail a list which highlighted priorities.

To ring-fence the content I created a sitemap as well as user flows and user personas. This allowed me to solidify ideas and develop them. Firstly by using a pen and paper, then evolving them into Sketch and InVision, in order to create an interactive prototype which could then be tested and refined.

Users Needs

  • Staying calm during public speaking or presentation.
  • Wanting to kick-start your body for a long day at the office
  • Somebody under pressure at work to meet a deadline
  • Student revising for an exam
  • Winding down at the end of a long day

Users Goals

  • Create an account to easily pair a new / existing device.
  • Capture the user’s resting heart rate or enter it manually.
  • Access a set of predefined rhythms, based on heart rate.
  • Change the predefined rhythms, create new ones and save them.
  • Sync their chosen rhythm with the device.
  • Find help when unsure how to use the app 
or device.
  • Control the device through the app interface, as well as 
the device.

Testing current app

Three people were chosen from a list of early adopters which Doppel provided.

Informal user testing sessions of 15-20 minutes were held using an iPhone and a Doppel wearable.

I sat alongside and observed the users as they engaged with the current app, and asked them questions based on their interactions with the interface.


Insights from current app testing:
Overall, the participants managed to get through the set tasks.

Main takeaways:

  • Individuals found the designs to be intuitive and easy to engage with
  • Industry terms such as cabin class, code-share and ancillaries were deemed confusing.
  • The page balance was weighted towards ‘accept’ over ‘cancel’ and ‘rebook’.
  • Breaking tasks up into digestible stages made the process more logical and easier to follow.
  • Overload of information and the help section was not easy to understand.
  • The brand colours were confusing and did not clearly define what the task was.
  • The lack of clutter and the streamlined approach was well received.
  • User understood the task they were being asked to completed.

Future Strategy

I evaluated insights and defined three main pain points that would lead the design direction for the revised app:

1. Interactions and content narrative

This was the primary issue. Users were confused about how to interact with the app and how it controlled the wearable. Some users commented that the look and feel was unsophisticated. A new UI Kit and design principles were established plus clear and simple interactions and properly labeled navigation were created.

2. Information architecture

The app was tricky to navigate and the information architecture needed a full review. 
A card-sorting session was undertaken to establish where the main site content should sit, with a new sitemap created to illustrate this.

3. Content review

Several users commented that the app instructions were confusing and screens were too text heavy. A review of the content on each screen was undertaken including the illustrations to ensure words and imagery balanced as well as making sure there was consistent use of terminology across the app.


I used lo-fidelity UI sketches to hammer out ideas and concepts and did some preliminary validation of these with some users. The feedback helped to refine the concepts.

User Flows

The main flows for the app were fleshed out in Sketch, using a higher-fidelity screen, and integrated into InVision. These illustrated how the main journeys within the app worked. It also allowed me to identify all the scenarios involved in the journey, such as alert messages, lost internet connection and any potential dead ends in the flow.

1. Sign-Up

Prototype and Insights

Using InVision, the screens were developed into a prototype which can be viewed here.

This was then taken back into testing. Three different people were chosen from a list of early adopters which Doppel had provided. Informal user testing sessions of 15-20 minutes were held using an iPhone.

The same tasks were undertaken as those used in the previous test session. There were a few caveats added to explain that the prototype did not offer full functionality and could not control the wearable device.

Overall, the feedback was positive. Some of the key insights were:

  • Two of the three participants said the body copy was too small.
  • There were no issues regarding navigation after I fixed the tray labels.
  • Too much content in some places. Despite cutting back some of the text, and introducing the animations, there were still two screens seen as being hard to scan and understand easily.
  • The new design meant interactions were now clear.
  • All three participants commented on how the animation in the on-boarding and set-up screens were very useful and helped with understanding the process.
  • Transitions and overall style were of a standard expected in a professional app.
  • All testers said they would definitely consider purchasing the device and downloading the app.


Doppel is a great wearable device with a well-designed app ready for release. The response to the app was very positive during testing.

Some improvements to be considered are:

  • The app redesign was approximately three weeks. This timeframe is too short to get the best insights from all types of users.
  • More thorough research and testing would probably be beneficial to future releases of the app.
  • Analytical data would be very useful but due to the newness of the app this was unavailable.
  • A further review of how the content within the app is performing would be very beneficial. During the redesign process, the copy was heavily edited and balanced with visual illustrations. However, users found during testing that the copy was still too prevalent on some screens.
  • Additionally, I think the set-up process for the app could be simplified, which in turn would assist with instructions within the app. However, this would require a hardware change so is unlikely to be prioritised for a while.