Building a Fitness Ecosystem? Learn how Kotlin Multiplatform cuts time, costs, and maintenance by more than 40%
by
Niek Haarman
on
Dec 23, 2025
Building a fitness ecosystem: why Kotlin Multiplatform is the smart choice for your fitness app
Building a fitness app today goes far beyond just the mobile product. For most fitness businesses, it’s about creating an ecosystem: an app that connects to hardware, handles performance data reliably, and scales across platforms.
This is where many fitness companies run into a familiar and expensive problem.
The fitness app development dilemma: two native apps vs cross-platform solutions
To reach the full market, you need both iOS and Android. Traditionally, that has meant either building two fully native apps, which doubles development time, cost, and maintenance, or hiring larger teams to manage both platforms.
Alternatively, businesses often turn to cross-platform frameworks that promise faster delivery with a single shared codebase. While this approach can reduce upfront costs, it often results in apps that feel generic, less reliable, and fail to deliver a truly native experience on each platform.
In fitness, these compromises hurt more than in most industries. Performance data, real-time feedback, and hardware connectivity leave little room for error. When an app feels “off,” users notice immediately and so do your retention numbers.
Kotlin Multiplatform (KMP): a better approach for connected fitness apps
At MoveLab, we use a cross-platform solution that has proven to offer significant advantages for both our team and our customers: Kotlin Multiplatform (KMP). This technology allows us to share core business logic across platforms while delivering fully native iOS and Android experiences. The result is faster development and lower costs without sacrificing performance or user experience.
KMP differs fundamentally from many cross-platform frameworks. It compiles directly to multiple native targets rather than building a layer on top of iOS or Android. This ensures stability, compatibility, and long-term performance which are all critical for connected fitness apps.
Why MoveLab uses Kotlin Multiplatform for fitness app development
Fitness apps are rarely “just software.” They often sit at the center of complex ecosystems that include hardware, sensors, live data streams, and performance metrics. This is especially true for fitness equipment manufacturers building companion apps for bikes, rowers, or treadmills.
Different operating systems handle connectivity differently, which is why many manufacturers struggle with inconsistent behavior across devices. At MoveLab, our connections library is built with Kotlin Multiplatform. The logic that handles communication between the app and the machine is written once and works consistently across iOS and Android. Bugs are fixed once, not twice, reducing platform-specific issues and simplifying maintenance.
User experience is another critical consideration. While some frameworks allow shared UI across platforms, we prioritize native interactions. Each platform gets its own native interface, while the underlying business logic remains consistent.
The biggest advantage of KMP is clear: core logic is written once and reused across platforms. Complex algorithms, connectivity flows, and business rules need only be implemented a single time, reducing the chance of bugs and inconsistencies.
For our clients, this typically results in a 40–45% reduction in initial development time, and as a result, costs. Because iOS and Android development happens in parallel, apps can launch on both platforms simultaneously, capturing the full market from day one. Over time, maintenance is more efficient, as fixes and improvements are applied once rather than twice.
Comparing approaches to fitness app development
Feature | Two native apps (iOS + Android) | Kotlin Multiplatform (KMP) |
|---|---|---|
Development cost | High – requires separate teams or larger team | Low – shared core logic |
Development time | Long – separate builds for each platform | Reduced – shared logic allows parallel iOS/Android development |
User experience | Fully native, optimized for each platform | Full native experience |
Maintenance | Complex – fixes and updates must be applied twice | Simplified – fix once for core logic |
Best suited for | Enterprise apps with complex requirements | Performance-critical apps, connected fitness, apps needing hardware integration |
Hardware / connectivity reliability | High – native integrations per platform | High – shared core logic ensures consistent behavior across devices |
Why choosing the right development partner is critical
Kotlin Multiplatform is not a shortcut you can add later. It requires deep expertise in native development, careful architecture, and an understanding of the challenges specific to fitness apps. Choosing a team that knows how to implement KMP properly results in:
Fewer compromises
Lower development costs
A stronger foundation for your fitness ecosystem
Faster time-to-market
Easier scaling
MoveLab’s clients don’t need to choose Kotlin Multiplatform themselves, we make that decision for them, as our connections library is built on this technology. The technology works quietly in the background, while the business benefits are visible from day one.
