Invoy Mobile App
Modernizing the Android experience for a breath-based metabolic wellness platform — connecting a next-generation breath-analysis device to daily progress tracking, data visualization, and analyst-supported coaching.
Overview
Invoy is a metabolic wellness platform built around breath chemistry. Users perform a short morning breath test with the Invoy device and a single-use breath pod, the mobile app turns that reading into a daily metabolic score, and coaches review breath scores and lifestyle patterns to provide tailored guidance.
As Senior Android Developer through GoatBytes.IO, I helped update the Android application for Invoy’s next generation of hardware and firmware — focusing on reliable device connectivity, daily progress tracking, data visualization for users and analysts, and architecture improvements that made the app easier to evolve as the product matured.
Why breath chemistry
Acetone is exhaled in trace amounts whenever the body breaks down fat for fuel, which makes breath acetone a noninvasive proxy for metabolic state. The appeal for a consumer wellness product is convenience: a daily breath test fits into a morning routine in a way that finger-stick blood draws never will.
Independent researchers have flagged that consumer breath-acetone devices vary in calibration and validation rigor, so the engineering brief was not to make medical claims — it was to give users and Invoy’s analyst team a reliable mobile surface for the readings the device produced, plus the daily-habit and trend tooling that turns isolated measurements into behavioral feedback.
- Noninvasivebreath biomarker for fat-metabolism stateAnderson, Obesity, 2015
- “Few”commercial breath-acetone devices have been thoroughly validatedAlkedeh & Priefer, Biosensors, 2021
- FDAgeneral-wellness category — not a medical deviceInvoy Wellness
- ~3 ppmreported breath-acetone shift between fed and fasted statesAnderson, Obesity, 2015
What sets it apart
A reliable bridge to the breath device
The Android app communicates with Invoy’s breath-analysis hardware over Bluetooth Low Energy, walks the user through pod insertion and the morning test, and handles the measurement-state machine so a daily reading lands in the app without ceremony.
Daily progress, not just data points
Each breath test becomes a daily metabolic score, plus trend visualizations and statistical summaries the analyst team uses to connect behavior with measurable change — turning a hardware reading into a feedback loop the user can act on.
Refactor toward a maintainable mobile core
The mobile app had to ship alongside a new generation of hardware and firmware, so the work was as much modernization as feature delivery — moving toward a cleaner, MVVM-based Android architecture so the codebase could keep pace with the product.
My role
As Senior Android Developer through GoatBytes.IO, I partnered with Invoy and UpTech Studio to update the Android application for the next generation of Invoy’s breath-analysis hardware and firmware. The work focused on the Android mobile layer: device connectivity, application architecture, daily progress tracking, data visualization, and the user-facing experience that connected hardware readings to Invoy’s coaching program.
- Updated the Android application for next-generation Invoy breath-analysis hardware and firmware
- Implemented Bluetooth Low Energy device connectivity for the daily breath-test workflow
- Built daily progress tracking and trend visualizations for the user-facing app
- Implemented statistical summaries that supported the analyst-facing coaching workflow
- Refactored the Android codebase toward a cleaner, MVVM-based architecture for maintainability
- Collaborated with firmware, product, and analyst teams to keep the mobile experience aligned with the broader Invoy program
Capabilities
- Bluetooth device connectivity
- Guided morning breath test
- Daily metabolic score
- Trends & journey tracking
- Analyst-supported coaching
- Lifestyle & behavior logging
- Statistical summaries
- Firmware update flow
- Wellness-grade data handling
- Onboarding & device pairing
- Notifications & reminders
- Account & profile
Distributed across
Built on
- Languages
- KotlinJava
- Mobile
- Android SDKAndroidXMaterial
- Architecture
- MVVMLayered domain/data/presentationLifecycle-aware UI
- Device & connectivity
- Bluetooth Low EnergyNordic Android-BLE-LibraryCompanion device protocolFirmware integration
- Domain
- Breath-acetone measurement workflowDaily metabolic scoringTrend visualizationAnalyst-facing statistics
- Platforms
- Android
Further reading
Public sources framing Invoy’s product, the science behind breath-acetone sensing, and the engineering engagement.
- Invoy — Metabolic Health Through Breath Chemistry AnalysisInvoy, current product siteCurrent product positioning: device + mobile app + coaching program built around a daily breath test.
- Invoy WellnessInvoyWellness-product framing — Invoy describes the device as a general-wellness product, not a medical device.
- Unlocking the Science in Your Breath with InvoyGoatBytes.IO case studyConsultancy-side write-up of the Invoy engagement, including BLE, Nordic Android-BLE-Library, Kotlin/Swift, and MVVM.
- The Ketogenic Diet: Breath Acetone Sensing TechnologyAlkedeh & Priefer — Biosensors, 2021Review of breath-acetone sensing — convenience and noninvasive appeal, plus calibration and validation gaps in commercial devices.
- Measurement of breath acetone for monitoring fat lossAnderson — Obesity, 2015Foundational clinical context for breath acetone as a noninvasive marker of fat metabolism.
“Turning breath chemistry into daily metabolic insight — a mobile layer for the device, the daily habit, and the coaching loop.”
Senior Android Developer · GoatBytes.IO · Invoy
Aug 2018 – Jun 2019
This case study covers the Invoy product engagement, delivered through GoatBytes.IO. The full role detail — other clients, scope, and consulting context — lives on the experience page.
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