they asked for a tablet app. users needed a mobile too

the brief was a tablet app that works fully offline

Design a cross-platform tablet app for service technicians so they could use it offline.

• Sensitive equipment

  In some areas, rules ban connected devices near the equipment technicians assemble or fix.

• Restricted sites

  Some places don’t allow any device with a signal inside, for example a military plant or a high-tech medical laboratory.

• No connection at all

  Some sites are simply too far from anywhere, for example a wind farm in the middle of the North Sea or a mine in the Canadian woods.

for some customers, the app was a condition

Some of Quanos’s customers asked for the app. For some, it was a condition of becoming, or staying, a Quanos client. Quanos was rolling out the InfoTwin cloud platform as its main tool, and this app was to be its companion.

In the first idea, the app connected to InfoTwin, where the documentation lives, and technicians had to choose what to download without being able to tell if it was the right documentation.

the brief came from the people who buy the tool, not the people who use it

Like most B2B software companies, Quanos talked to the managers who choose the tools their teams use. The managers asked for a tablet app for offline work with documentation, and that became the brief. Nobody had asked the service technicians what they need in the field, or how they work with documentation.

what I assumed going in

Before the interviews, I set six hypotheses to test.

1. 01Service technicians are equipped with protective clothing that makes it difficult to use touch devices
2. 02Service technicians are using touch devices like tablets while working in the field
3. 03Service technicians often face challenges with internet connectivity while working in the field
4. 04Service technicians frequently search through the tool for the required content
5. 05Service technicians prepare for their visits in advance
6. 06Service technicians are interested in collecting specific parts of documentation and other content items into custom groups

from first interview to handover in 5 months

8 interviews with the people in the field

I conducted 8 in-depth remote interviews to gather qualitative data to uncover pain points and user needs across different work environments.

what the technicians told me

• Laptops do the real work. Tablets barely came up.

  Laptops run the documentation and specialized tools. Tablets and mobile devices are hard to use one-handed, and some sites ban devices with cameras.

• PDFs rule, but they go out of date.

  PDFs are the main format, but they can be outdated, and some clients ban them. Technicians keep their own notes in OneNote⁶.

• Finding the right page is the hard part.

  Search in today’s tools is unpredictable. Technicians prefer 3D and tree views to move through a document.

• Dust, oil and gloves beat touchscreens.

  Rough conditions ruin laptops, and gloves make touchscreens hard to use. A mobile, though, fits in a chest pocket.

• No signal means paper.

  Technicians find the documentation in the office, print it and carry it to the machine. They want offline tools that do everything the online ones do.

• Screenshots replace search.

  Rather than search big documents again, they screenshot the parts they need and share them.

• What they want most.

  Fast search for parts and documents, content that works offline on mobile, and a way to prepare for visits.

one persona to design for

Meet Alex Meyer, a persona I built from the eight interviews.

Persona · from 8 interviews

Alex Meyer

Field Service Technician

Alex often goes abroad to meet technicians on the client’s side. Besides being responsible for assembling machines there, Alex is also involved in the maintenance process, so they have to know the specifics of particular machines and their repair history.

• Travels abroad
• Assembles machines
• Knows each repair history

Their goals

• Create and organize personal notes and information sets in advance, ensuring they have all necessary materials and a clear understanding of the content before arriving on-site.
• Utilize tools and content that are accessible offline to maintain efficiency in areas with severe conditions and limited connectivity.
• Identify necessary spare parts and quickly understand how to change/assemble them without spending the entire day in the office at their laptop.

Their main pain points

• Difficulty navigating static PDF documentation and finding specific parts.
• Needs to contact their lead when they can’t find the necessary information.
• Connectivity issues in remote locations, limiting access to online tools.
• Challenges with outdated documentation and lack of real-time updates.
• Limited offline functionality and poor mobile optimization in current tools.

7 challenges to solve

Designing a companion app, I focused on these key challenges:

• Same online & offline capabilities
• Navigation that doesn’t need explanation
• Clear search
• Efficient space management
• Ensuring that there is always updated documentation on the device
• Multi-tenant management
• Mobile optimization

Quanos took the app to mobile as well

Based on these insights, I presented findings that led Quanos to reprioritize their strategy for the mobile version of the app.

Quanos had planned to release the app for tablets only. Before I left, the team told me the report had changed that plan, and the app now runs on mobile too. Two of my recommendations from the report have happened since:

• Conduct usability tests on this first iteration of the design
• Adapt the design for mobile

online when you can, offline when you must

Instead of downloading blind, I proposed an online and an offline mode. Online, it works on its own, not just as an add-on to the cloud platform: technicians search for the right documentation, preview it, then decide what to download and keep on the device. In the field, they switch the network off and keep using what they downloaded.

It’s how a streaming app like Netflix⁷ works: watch while connected, or download and keep watching offline.

Material You, adapted for gloves and dirt

The goal was a cross-platform app, optimized mainly for iPads and Microsoft Surface⁶, with extended support for desktops and mobile. I built the UI kit on Google’s Material You, the design system that comes with Flutter. I compared it with Apple’s Human Interface Guidelines (HIG), then adapted Material You for how technicians actually work: on tablets, in tough conditions.

• Gloves

  Technicians often wear protective gloves, which make small targets hard to hit.

• Dust and oil

  Devices get extremely dirty on site.

• Stiff touchscreens

  Some devices, especially cheaper Microsoft Surface tablets, need a hard press to register a tap.

• Bigger buttons

  The biggest change came straight from the interviews. Material’s stock button is 40 px tall; the new one is 46 px.

Quanos extended the project from 4 to 5 months, adding research and usability test preparation that weren’t in the original scope.

ready for testing, then handed over

My involvement concluded just as the usability tests were about to be scheduled. I completed all the preparations and handed everything over to the new designer.

Quanos decided to bring design in-house and hired a designer. In my last two weeks I onboarded him: first the product, the design system and the decisions behind it, then the research and the tests. It was his first usability test; he ran it and presented the report.

the app shipped, and almost all of the design is still in it

The app came out on the App Store⁵ as InfoTwin in November 2024, reached version 1.0 in May 2025 and is still updated. Offline downloads, search and filters, spare parts and documents are all in it. Almost all of this design is still in the app today.