App Development Partner for US Companies
Your product is great. Your app should be too. We build apps for US companies – from branded apps for your service to apps that connect to your hardware and devices. And stay with you as your technical partner.
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Why US Teams Choose Us?
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9+ years in EV, IoT, fitness, and healthcare
Since 2017, we've built apps for fitness makers, e-mobility companies, connected product brands, and digital health platforms. We know what your customers expect and what makes an app succeed in your industry. You don't pay for our learning curve.
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We're building products for the US market
Our work includes the console app for premium STEPR stair climbing machines; the Force USA training app for equipment sold in 30+ countries; and a branded app for Norsk Guardian, a US maker of lithium marine batteries.
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We work around your schedule
We're based in Europe and organize our days to overlap with US business hours. Calls, demos, and reviews happen during your working day, and development continues while your team is offline.
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20+ connected device models integrated
Stair climbers, e-scooters, smart batteries, rowing machines, and more. When you launch new models or switch suppliers, your customers keep one app that simply works.
App Development Services We Provide

Force USA (design by Stormotion)
Discovery & Product Scoping
Your business is already running, and you see how an app could bring more value to your customers. But the scope, ROI, and budget are still unclear. We run a focused discovery to define what the app should do and what it takes to build it. For connected products, we test a proof of concept on a sample device. You get a concrete plan, phased roadmap, and realistic budget before app development starts.
Problem and user flow definition
Technical feasibility check and proof of concept
Phased roadmap with priorities
Budget estimate by phase

Egret (design by Stormotion)
Cross-Platform App Development
Your users are on iOS, Android, and the web, but separate apps for each platform would double your costs. We build one React Native codebase for iOS and Android, plus the web app, admin panel, CMS, and backend behind it. You get a complete product on every platform your users need, maintained by one team.
iOS and Android from one codebase
Web app, admin panel, and CMS
Backend and API development
Apps for Apple Watch and Wear OS

Norsk Guardian (design by Stormotion)
Companion Apps for Connected Hardware
Your device works, but the app is what users touch every day. And unstable connections or failed updates can quickly turn into bad reviews. We build apps that connect reliably to your devices, support all your models and firmware versions, and let customers update their device right from their phone. You get a stable app that works with your hardware from day one and keeps working as your lineup grows.
Stable connection through BLE, Zigbee, Matter, Thread, and Serial protocols
Device updates right from the app
Multiple models support in one app
Testing on real devices

STEPR (design by Stormotion)
Embedded Android, Kiosk & Terminal Apps
Your device has a screen, and it needs software that feels as premium as the hardware. We build apps for fitness consoles, kiosks, and payment or charging terminals that control the device and guide your customers through every step. You get a branded on-device experience you can update without Google Play.
Custom Android console and kiosk apps
Device control and payment integration
App updates without Google Play
UX designed for device screens

design by @Equal
White-Label & OEM App Replacement
Your hardware or service is premium, but the generic vendor app isn't. Every change depends on the vendor, and you have no direct relationship with your users. We replace white-label and OEM apps with your own branded app built around your business logic. You get full control over features, branding, and user data.
Branded UX that matches your product
Custom features and loyalty logic
Direct access to user data and analytics
Support for your existing devices and protocols

Mindance (design by Stormotion)
App Rescue & Modernization
Your app works, but every release is a risk to break functionality and new features take twice as long to implement. We review the codebase, tell you honestly what to fix now and what can wait, and modernize the app step by step without stopping your releases. You get faster, safer releases and an app your team can keep building on.
Codebase and architecture review
Prioritized fix and modernization plan
Fixes for unstable device connections and failed updates
Monitoring where customer issues come from

Caspar Health (design by Stormotion)
Ongoing Development, Maintenance & Support
Your app is live, and it needs regular updates, new features, and someone who reacts fast when something breaks. We ship new features, keep the app compatible with new OS and SDK versions, and fix bugs. Team capacity scales up for active development or down to maintenance as your roadmap changes. You get a team that already knows your product, whenever you need it.
New feature development
OS, SDK, and library updates
Bug fixes and monitoring
Flexible team structure and capacity
Products We've Built for the US Market
Our Industries
Fitness
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IoT & Connectivity
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EV & EMSP
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Healthcare & Mental Health
Learn moreHow We Support US Teams
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Partner mindset & co-creation
We don't just close tickets. We challenge assumptions, suggest better approaches, and align with you on measurable product goals.
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Full intellectual property transfer
The code, designs, and documentation we create belong to you. No lock-in.
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Fast start without recruiting overhead
Skip months of hiring. Our engineers join your project quickly, with minimal onboarding on your side.
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Your product knowledge stays with us
We document architecture, decisions, and device behavior as we go. If an engineer changes, the knowledge stays with the team.
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Stable connection for your customers
We host and configure your app's servers in the US, so it loads quickly and stays reliable from coast to coast.
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We test on your actual hardware
Our QA engineers test real devices and firmware versions together with the developers who build the integration. We handle the shipping logistics with you.
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L3 support for your L2 support
When a customer reports a problem, we quickly find whether it's the app, the device, or the connection and fix it. Your support team handles the customer; we handle the technical side.
Our Tech Stack
Frameworks
Programming Languages
Navigation
Networking & APIs
Backend & Data
State & Data Fetching
Payments & Monetization
External Devices / IoT & Connectivity
Maps & Location
Graphics, Video & Audio
Forms & Validation
Internationalization
Analytics & Monitoring
Testing & QA
CI/CD & Delivery
AI / Machine Learning
AI Coding Assistants
Admin & CMS
React
React Native
Expo
Gatsby
Next.js
Hasura
NestJS
What US Clients Say About Us
How can we help?
Thank you
Your message has been sent.
Our manager will contact you as soon as possible. Have a nice day!
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Book a call with our Co-Founder, Roman, to explore your project.
How We Work With US Teams
Pre-Project
Discovery Stage
Planing
Agile Development
UX-Prototyping
Design
Development
QA & Testing
Transition
Maintenance
Handover
Next Iteration
We take all product delivery responsibility and offer you a full-cycle team (full-time engineers and part-time UI/UX designer, QA, and PM).
You need this if:
- You're launching a new app and want one team accountable for the build
- You're rebuilding a legacy app or modernizing an existing product
- You have a specific product stream, module, or domain that needs its own dedicated team
Why US Companies Stay With Us
Let's build your next product together-
3.2 years average partnership
Long-term collaboration is our standard, not the exception.
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3.7 years average engineer tenure
A stable team and low churn mean the people who know your product stay on it.
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We adapt to your business pace
We plan team size around your budget cycle, scale down when you need a pause, and scale back up when you're ready to grow.
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We develop your app with you
New hardware models, suppliers, or firmware generations? We extend the same app and keep older devices working instead of starting over.
FAQ
How do you handle the time difference with US teams?
We plan our working day to overlap with US business hours, so calls, demos, and reviews happen during your morning. While your team is offline, development continues, and you start each day with progress to review. Updates arrive in your Slack or project tracker, so you always know what's done, what's next, and where we need your input.
Who owns the code and intellectual property?
You do. We transfer full IP rights to everything we build for you, including source code, designs, and documentation. You keep admin access to your accounts, app store listings, and cloud services. If you ever decide to bring development in-house or work with another partner, your team gets everything it needs to keep the product going without us.
Can you start before our hardware is finalized?
Yes. Many connected products we work on start before the hardware is final. We begin with discovery and a proof of concept on a prototype or sample unit to test the riskiest parts first, like the device connection and data exchange. This way, problems surface early, when they're cheaper to fix. To build and test the full app, we'll need working devices, and we'll plan the shipping logistics with you.
Can you take over an app another team built?
Yes. We start with a technical review, available documents, and tell you honestly what needs fixing now and what can wait. Then we stabilize and modernize the app step by step without stopping your releases. You don't need the previous team's help to get started: we've taken over poorly documented apps before and rebuilt the missing knowledge as we went, documenting it for everyone who works on the product next.
How soon can you start my project?
Usually right after we agree on the scope. We begin with a kickoff to learn your product, goals, and current setup, then set up access and tools. Our team spends minimal time on onboarding and we document everything as we go. You can see first results within the first sprints.
How much does it cost to develop the app with you?
Our development unit usually consists of full-time developer(s) and part-time QA, UX/UI designer, and PM. The unit costs $10,000-$15,000 per month. Most projects take 4-8 months from discovery to deployment. So, the total is $40,000-$120,000.
But the price depends on the scope, the complexity of your product, and the team you need. Some clients need one engineer to join their existing team; others need a full team with design, QA, and project management. After a free consultation and discovery, you get a phased roadmap with a realistic budget for each phase, so you can decide before development starts.
Will we be able to communicate easily with your team?
Yes. Your team works directly with the engineers and project manager on your product, in English, without a chain of account managers in between. We use the tools you already use, whether that's Slack, Jira, or something else, and can join your standups and planning. You get regular updates and demos, so there are no surprises.
What does the contract look like?
We sign an NDA before you share any details, so you can talk openly about your product from the first call. The contract clearly defines scope, team, rates, and IP ownership, and we invoice in USD. You can scale the team up or down as your roadmap changes, without switching vendors.
How do you keep our data and product secure?
Access to your code, accounts, and customer data is limited to the people working on your product, and you keep admin rights to everything. When a team member changes or the project ends, we remove their access. Your data stays in your systems, and we work with it only as much as the project requires.
What happens after the app launches?
Launch is where most long-term work begins. We keep the app compatible with new iOS and Android versions, fix issues your customers report, and add features as your business grows.
If you need a pause in active development, we scale down to maintenance and scale back up when you're ready, with a team that already knows your product.


Jakob Hals
Director of Product Technology @ Norsk Lithium
"Stormotion stood out because of their focus on Bluetooth-connected products. They weren't just app developers, they understood the unique challenges of building mobile app experience for hardware products. Their collaborative approach, technical expertise, and ability to quickly grasp the vision of the North Guardian app made it clear that they were the right fit."