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Dev Station Technology

Mobile app development

Apps for people wearing gloves, not sitting on a sofa

Our mobile work runs on construction sites, in vehicle bays and in plant rooms. It holds up with no signal, reads values off test equipment over Bluetooth, and produces a document somebody has to sign.

Book a 30-minute scoping call See the field apps

We are not the right team for a consumer social app. We will say so early.

What a field app has to survive, tested before launch.
No signal for four hours Records queue on deviceHandled
Two engineers, same job Conflict rules agreed with youHandled
Reading from an instrument Bluetooth or vendor SDKHandled
Battery through a full shift Sync batched, not chattyHandled
Phone dies mid form Draft restored on reopenHandled
These are the tests that decide whether the app gets used.

Mobile work we have delivered

  • Hydrajaws LimitedTwo apps reading torque and pull values
  • Verify AutoAutomotive safety compliance app
  • German software firmReact Native alongside a web product
  • Norwegian EdTechXamarin app on a school platform

Where we fit

Field apps and consumer apps are different jobs

Both are called mobile development. They fail for completely different reasons, and are built by teams with different instincts.

Go elsewhere when

Growth is the hard part

  • Success is measured in installs and retention curves
  • The app lives or dies on visual polish and virality
  • You need App Store optimisation and growth loops
  • There is no hardware and no compliance obligation

Consumer studios do this better than we do, and we will say so.

Come to us when

The environment is the hard part

  • The user is on a site, in a bay or in a plant room
  • Signal is unreliable and losing a record is unacceptable
  • Values come off instruments rather than a keyboard
  • The output is a certificate, a report or a job
  • The app has to reach a system you already run

This is where our apps live. Every build below runs in the field.

Plain definitions

Two terms that get used loosely in mobile briefs

Both sound like detail. Both decide whether the app gets used after the first week on site.

What is a field service app?

It is an app built for someone doing a job away from a desk, usually against a defined procedure, usually producing a record somebody is accountable for. Jobs, inspections, readings, certificates.

The design constraints come from the environment rather than from the feature list. One hand free, gloves on, bad light, a phone that has to last a shift, and a supervisor who needs the result before the engineer gets back.

What does offline first actually mean?

Offline tolerant means the app warns you and stops. Offline first means the app assumes there is no network, writes everything locally, and treats a connection as an opportunity to sync.

The hard part is not storage. It is deciding what happens when two engineers edit the same record from two devices, and that rule has to come from how your team works rather than from us. We agree it before we build it.

What we build

Six things field apps need that consumer apps do not

Offline first, not offline tolerant
The app assumes no network and treats connectivity as a bonus. Records queue locally and sync with conflict rules you agreed.
Instrument integration
Torque wrenches, pull testers and gauges over Bluetooth or a vendor SDK. We integrated the KTC SDK for Hydrajaws so readings are captured, not typed.
Documents generated on device
Certificates and reports produced at sign-off, in the layout your client or regulator expects.
Identity that survives a shared device
Engineers pass phones around. We have run this through Azure AD B2C with roles that follow the person, not the handset.
Native or cross-platform, chosen honestly
Xamarin, React Native or native. We pick by what your team can maintain and what the hardware needs, not by what we prefer.
Store submission and distribution
Public store release or internal distribution, including the review cycles that catch teams out the first time.

What people ask us for

Six kinds of mobile build we are asked for

Our work clusters here. If your project is none of these, we will say so on the first call.

Inspection and checklist app
A defined procedure carried out on site, with pass and fail logic against measured values rather than ticks.
Instrument reading app
The phone talks to the test equipment over Bluetooth or a vendor SDK, so nobody transcribes a number. This is the Hydrajaws build.
Job and work order app
Assignments, status, time and parts, syncing back to the system that raises and bills the work.
Asset and certificate app
Scan the asset, see its history, produce the document at sign-off in the layout the client expects.
Companion app for a web product
Where the desktop product already exists and the field half is missing. We built React Native alongside a web product for the German client.
Free tier of a paid tool
A cut-down app that reaches the market and sells the premium one behind it. Hydrajaws ships free and premium from one codebase.

Tell us where the app has to work

Three fields. An engineer reads it, not a sales rep. You get an answer within one working day.

  • We map the environment, the devices and the output
  • You get a view on native versus cross-platform, with a cost band
  • No obligation, and no phone number needed to start

Our work

Two apps that go out on site

Case study, United Kingdom

An app that reads the tester instead of the engineer reading the dial

Hydrajaws makes portable pull testers. Their old app was poorly documented, they did not control the code, and the interface was holding back sales. We rebuilt it as a free tier and a premium tier from one codebase, put user management behind Azure AD B2C, and integrated the KTC SDK so torque and pull readings land in the record as measured.

  • Xamarin
  • .NET
  • Angular
  • Azure
  • Azure AD B2C
  • KTC SDK
Increase in potential clients after launch
500%
Tiers from one shared codebase
2
Digital torque testing opened automotive
New market

Case study, automotive

Safety compliance for a brand that is judged on its finish

Verify Auto needed an automotive safety compliance app where the interface had to match the brand as closely as the logic had to match the standard. We built it modular for scaling, integrated automotive APIs, and validated the design through prototypes with their stakeholders before writing production code.

  • Xamarin
  • .NET
  • Angular
  • Azure DevOps
  • Azure AD B2C
Design validated before production code
Prototypes
Built for scaling across the range
Modular
Cross-industry move from construction
Automotive

How the work runs

The device tests come first

  1. Week 1

    Environment and devices

    Where it is used, which handsets, which instruments, and what happens with no signal. Instrument models get checked before anything is promised.

  2. Week 2 to 4

    Flow and prototype

    Screens designed for one hand and poor light, tested as a prototype with the people who will use it.

  3. Week 5 to 12

    Build and field pilot

    A real crew uses it on real jobs while we are still building. Demo every two weeks.

  4. Release

    Store or internal distribution

    Submission, review cycles, and a rollout plan that does not strand engineers mid shift.

Technology and integration

What we build on, and what the device has to reach

Chosen by what the hardware needs and what your team can maintain, not by preference.

Cross-platform
Xamarin and React Native on Android and iOS. Native modules where a platform feature has no bridge worth trusting.
Device and instrument link
Bluetooth Low Energy profiles and vendor SDKs. We integrated the KTC SDK for digital torque and pull readings.
Local storage and sync
On-device storage with a queue and conflict rules, so a full shift with no signal loses nothing.
Identity
Azure AD B2C with roles that follow the person rather than the handset, which matters when engineers share devices.
Documents on device
PDF certificates and reports generated at sign-off, in your layout, available before the engineer leaves site.
Back end and distribution
.NET or Node.js behind the app, and release through the public stores or internal distribution for staff-only apps.

Who does the work

Twenty engineers, eight of them senior

Field apps fail in ways that only show up on a roof or in a plant room. The engineers who build ours have spent enough time on instrument integration and offline sync to know where those failures hide.

Engineers in Ho Chi Minh City
20
Senior engineers
8
Average experience
5+ yrs
Working with US, UK and EU teams
10+ yrs

You interview whoever we put forward. Ask them what happens when two engineers submit the same job from two devices, and judge the answer.

How we work

Five engagement models, and you pick how much you keep

The models differ in one thing: how much of the management you hand over. Everything else, including who owns the code, is the same in all five.

Changing model later is normal. Augmentation into a dedicated team is the common direction, and the people stay.

Engineers join your team and work inside your process, your board and your code review.

Team control
You manage the day to day
Pricing
Monthly per person, by role and seniority
Minimum
1 month

A team that works only on your product, with a lead on our side running delivery.

Team control
Shared. Our lead runs delivery, you set priorities
Pricing
Monthly per role, lead included
Minimum
3 months

A long-term engineering site under your standards, where we carry recruitment, HR, payroll and equipment.

Team control
You direct the work, we run operations
Pricing
Monthly per role plus site costs
Minimum
6 months

One price for a scope that is genuinely settled, with the overrun carried by us.

Team control
We deliver, you accept against written criteria
Pricing
Fixed bid, paid against milestones
Minimum
Project based, usually 10 to 14 weeks

Everything in the centre model, with the whole team moving into your own Vietnamese entity on an agreed date.

Team control
Transfers from us to you
Pricing
Monthly per role, transfer price agreed up front
Minimum
2 to 6 years

FAQs

Questions we get on the first call

Native or cross-platform?

Cross-platform unless something forces native. We have shipped Xamarin and React Native. The deciding factors are usually hardware access and what your team can maintain, not raw performance.

Can the app read our test equipment?

If the device exposes a Bluetooth profile or a vendor SDK, yes. Send model numbers and we check each one before you commit.

What happens with no signal all day?

Everything captures locally and syncs later. We agree the conflict rules with you, because what should happen when two people edit the same record depends on how your team works.

Do you handle App Store and Play Store submission?

Yes, including internal distribution where the app is only for your own staff.

Can it produce certificates on the device?

Yes. PDF generated at sign-off in your layout, available before the engineer has left site.

Who owns the code?

Your company, entirely. We hand over repositories and documentation on request.

How much does a field app cost, and how long does it take?

A single-purpose app with one integration is usually 10 to 14 weeks. Add instrument integration, certificates and a supervisor portal and it runs longer. Instrument work moves the number most, which is why we check your device models in week one. What you pay depends on the engagement model above, and you get a figure after the scoping call.

Will it run on rugged handsets and scanners?

Usually yes, if the device runs a current Android or iOS build. Rugged handsets from Zebra, Honeywell and similar makers are ordinary Android underneath, though hardware scanner buttons and any vendor-specific SDK need checking per model. Send the models with the enquiry.

How do we update engineers who never come to the office?

Through the store or through your mobile device management, depending on whether the app is public or staff only. We plan the rollout so an update never strands somebody mid shift, which usually means the old version stays valid until the job in progress is submitted.

Tell us where your people work

Site, bay, plant room or roof. What the environment demands decides most of the build, and it is the first thing we ask about.

Book a 30-minute scoping call Read where we do not fit

Let's Talk