Building Zerigo Patient-Facing App

Zerigo Health contracted a small design team to transform its mobile app for patients managing chronic skin conditions. By overhauling the app’s information architecture structure, visual design branding, and introducing new confidence-building features, we supported 20% higher treatment adherence and elevated the platform’s overall clarity and trustworthiness.

Two phones with Zerigo App redesigns. Left screen shows a weekly calendar with green buttons for "treatment" and blue bottons for "progress check". The right screen shows a progress check slide with likert scales to rate symptom severity

Team Structure

Business SVP

Head of Development

Software PM

2 Designers

Process

Usability Testing + Eval Research

Information Architecture

Visual Design

App/Product Development

High-Fidelity Prototyping

Problem

Zerigo Health offers light-therapy for chronic 
skin conditions. Patients are given a portable device, a care guide, and an app to understand and track their path to remission.

The app equips patients with tools to manage chronic skin conditions—yet the experience of using the app didn’t match the quality of the care it aimed to support. Despite having a functioning product, the app’s usability issues stood in the way of meaningful, confident engagement.

What we delivered

We redesigned Zerigo’s core experience, while fleshing out new components, to eliminate confusion, speed up time to complete tasks, and rebuild patient trust.

Removing guesswork from dosages

We distilled complex medical guidance into clear, actionable steps—so patients didn’t have to “figure it out” themselves. Reduced overall number of clicks on progress updates and treatment, helping patients want to log this information.

Visualizing progress for higher confidence

Adding in a dedicated photo portal allowed users ability to actually compare and notice slow progress. They could see when and why images were needed—building trust instead of skipping out on this crucial offer.

Smarter data, better predictions

Visual depictions and standardized naming conventions replaced overwhelming lists when adding body locations to reduce decision fatigue and bad data that helped inform personalized remission timelines.

Simplified flows = higher engagement

By streamlining the entire app, we made it faster and more intuitive, helping users spend less time navigating and more time focusing on their treatment. The simplified interface allowed patients to engage with their care in a way that felt seamless and stress-free.

Research

Conducting evaluative and usability research identify key changes for a more functional app.

Why redesign?

Though the company had already developed a working app, users faced significant challenges in navigating the interface and accessing key features effectively. The app lacked clarity, inclusivity, and accessibility, which ultimately affected its value and usability for a wide range of users. These gaps in design, including unreliable data logging, complex navigation, and unclear language, were undermining the app’s potential to meet user needs.

Two screens, one showing calendar homepage with poor spacing and no hierarchy, second showing a dashboard for progress check-in that is confusing with too many images and no hierarchy

Progress check UI issues

  1. Users don’t understand what the emoji check-in means

  2. Inconsistent naming conventions, hard to keep track of where they are and what they mean

  3. What do the likert tags mean? Define severe vs. mild

  4. Sometimes photos are required, and other times not. How to tell? No tagging of requirements

  5. Not all skin conditions look like the available options, unsure how to proceed without a relatable sample

The progess check screen with red boxes outlining the 5 key issues

Make it purposeful, respectful, and clear

Every interaction should feel essential—not like a hurdle. Patients come to treat, not to troubleshoot. Progress checks must be quick, clearly explained, and respectful of their time, privacy, and intelligence. If users don’t see the value, they’ll skip the flow. If they don’t understand it, they’ll drop off. We owe them clarity, control, and a sense that every step moves them closer to remission.

I truly dislike your ‘progress checks’ and particularly my most recent which required a photo. I have a physician and really shouldn’t be subject to that type of privacy invasion. I would like to decline all other ‘added services’ and troublesome invasions.

Dose adjustment UI issues


  1. Users admitted to skipping this chunk of text

  2. Users hesitated on what to do here; why click on what they needed to change?

  3. What is the prescribed initial dose? Why does the user have to select this information themselves-- isn’t this dangerous?

Treatment page with three red boxes showing UI errors. Page shows a big chunk of text explaining what to do, then the body part with three circles to click from with options to increase, maintain, or skip dose. A continue button is at the end.

Remove all guesswork

Patients should never have to interpret or decide their own treatment path. The app should act as a trusted extension of their care—not shift clinical decisions onto them. Clear, confident guidance for each body part, without overwhelming instructions or choices, is essential. Every step should feel safe, supported, and personalized—so users can focus on healing, not second-guessing.

How am I supposed to proceed from here? I don’t know if I should increase or maintain or skip because I don’t remember from my last symptom check-in? This is my problem.

Treatment flow UI issues


  1. Improper padding, inconsistent styling

  2. Newer users weren’t sure what to click and 
what to do based on the display

  3. Start treatment of what body area?

Shows the treatment page. A small button to add new body locations, and 6 white squares with orange arrows on the left-hand side and green boxes with small font doses under. At bottom a big green "start treatment" button, but for what?

Easily treat and add
body locations

New users should never feel lost or unsure of what to do next. Each step must clearly guide them without confusion or ambiguity. By simplifying buttons and making choices easy to understand, we ensure users can move through the flow with confidence and clarity. Every interaction should be self-explanatory, removing any need for users to second-guess their actions.

I generally treat at the end of my day, I just want start treating with least amount of effort possible. Sometimes it will take me more than an hour to do my treatments and requiring me to do more is a burden.

Design Iteration

With a tight budget and tight timeline, we jumped right into visual design and iterating on concepts for the entire app, focusing with the key features.

App at a glance

With four main features, key tasks were buried. Here is the streamlined version of the app we created.

Progress check

Intended to rate symptom severity and add progress photos to help inform treatment doses (or if treatment was even safe this session).

Message center

Allows patients to interact with their care team to ask questions and adjust treatment schedules and timelines as needed.

Treatment logigng

Patients can identify body parts that have a skin condition they want to treat, and then visit this feature when it comes time to treat to know the dose and how long to use the device.

Photo archive (not built yet)

This was not operational at the time we were contracted, but intended to help users visualize their progress and compare where they are on one day vs. another.

Flowchart showing app's information architecture. From home you can click progress check (to then rate symptom severity), treatment logging (to treat for the day), messages, and photos (to see all photos by date).

Homepage iterations

Adding a body location

Treatment and dose adjustment

Two app screens for the treatment and dose adjustment

Final screens

The final screens for developer handoff.

Key screens

Three key screens: The new calendar home page, with accessible colors. The messages app with a blue gradient top and easy to read messages, and a photo calendar with two big photos of skin lesions.

Progress check

3 progress check screens: 1 asks "how severe are your symptoms today" with clickable likert scale from severe to clear, submit button at bottom. 2 shows a photo upload option with greyed-out submit button or skip option. 3 is completed uploads.

Adding body part

Adding a body location with a clickable human body with head selected, then app prompting photo upload of skin area

Treating body part

1: lists treatment areas with availability and treatment count. Middle: selected one body part with start treatment button appearing at bottom. 3: Treating timer modal with warning and stop treating button

Impact & Takeaway

How our redesigns impacted users, the business, and what I learned.

Impact

20% increase in treatment adherence

By simplifying daily check-ins and removing unnecessary steps, we turned logging into a quick, repeatable habit that patients could sustain.

Frictionless check-in

We streamlined the check-in and treatment process by reducing clicks and adding skip options, making it easier for patients stay engaged and finish treatment.

Smarter, safer inputs

By standardizing body part inputs (avoiding nicknames), we streamlined the data collection process, enabling Zerigo engineers to more accurately predict remission timelines.

Challenges

Fighting for basic UX

Business stakeholders are... business stakeholders! Ideally more rounds of usability testing, research, and iterations to make a more robust app.

Streamlining everything

Having to distill medical information into clear, concise instructions. Still a work in progress when we wrapped, to make sure everything was safe.

Strict timelines

With the business stakeholders wanting to ship features quickly, we weren’t able to iterate and refine designs (or test) as much as we intended.

Takeaways

Zerigo was my first design job, and it shaped so much of how I approach projects now. I learned how much a solid information structure and clear, thoughtful visuals can actually build trust—especially when you’re asking someone to stick with a long-term health plan. It was my first deep dive into balancing business, medical, and user demands… and it made me fall in love with solving messy problems through design that feels calm, human, and confident.