Fitness Tracking App Development with .NET MAUI

We have executed the development of mobile and desktop applications from one code base, demonstrating our ability to develop scalable cross-platform applications and create modern fitness technology solutions for use cases in real-world production.

In today's rapidly evolving lifestyle, staying fit is no longer just about going to the gym, it is about creating, utilizing, and having access to a digital ecosystem that supports users daily through guidance, tracking, and motivation.

The creation of AquaFit was performed with this vision in mind of offering a complete fitness solution and platform for fitness enthusiasts, yoga practitioners, and health-focused individuals.

The App available on both Android and iOS devices, providing the users with a superior user experience that brings together all components of fitness, including guidance, nutrition planning, tracking of activities, and integration with smart devices. It acts as a fitness trainer, nutritionist, and health tracker, all in one.

AquaFit is a digital fitness app providing a complete fitness experience that connects aquatic workout programs, land-based workout programs using yoga techniques, and has the ability to track holistic health and wellness.

The app has been created with the use of .NET MAUI (Multiplatform App UI), allowing users to experience a single unified interface regardless of whether they are on iOS, Android, Windows, or macOS desktop devices.

AquaFit meets the needs of fitness enthusiasts today by providing a complete fitness plan including a structured approach to fitness training and nutrition, providing tools to track health and fitness using wearables.

Target user is someone who loves fitness & yoga and does the following:

• Participates in high-intensity land exercise (strength training, HIIT) and low-impact water exercise.
• Requires a proper guide to avoid injury and help with progressive overload.
• Wants a personalized meal/supplement plan to fit their level of activity.
• Uses a fitness tracker (e.g., heart rate monitor, smartwatch) for tracking workouts, but has trouble maintaining a complete record of workouts using both water and land-based sessions.

Current apps either track land-based exercises exclusively or do not provide adequate tracking of water workouts and cross-sync between devices.

The .NET MAUI development model has allowed the project team to create a single shared code base for UI and business logic and to deliver a native experience with performance characteristics on all six target platforms, including:

• Mobile Platforms: iOS (15.1+), Android
• Desktop Platforms: Windows (11/10), macOS (12.0 with M1 and later)
• Core Features: Offline synchronization, accessing the camera for verifying input into forms, and using SQLite for the local database to track workouts.

Implementation Details:

• Appropriate design pattern was used for the application - MVVM and CommunityToolkit.MVVM for observable properties.
• Native APIs were utilized to create responsive layouts using Microsoft.Maui.Controls (that adapt to phone, tablet and desktop).
• Platform specific integrations were performed with: Apple's HealthKit for iOS, Google Fit for Android, and Microsoft Bluetooth Stack for both Windows and Mac.

Proper Fitness Demonstration Guide

3D Exercise Demonstrations (2000+):

Built using Webview hosting a set of assets in three.js. Tap to rotate on mobile and drag the mouse on desktop.

Progressive Workout Plans:

The app will assess the user's performance with spesific parameters (i.e. reps, weight, heart rate) and adjust the next workout session accordingly-acting as a personal trainer.

Yoga Flows:

Two flow types exist, one includes yoga performed in the water using the water for resistance, the other uses a yoga mat doing the same flows with the use of a timer for breath.

Integration of diet plans

• The caloric adjustment generator calculates your total daily energy expenditure according to the activity data (steps, swim distance, yoga time) synced to your device and suggests macronutrient breakdowns.
• You will be able to log your meals, by scanning the barcodes of food items (using the camera on your MAUI device) or entering them manually for homemade meals.
• Hydration reminders are critical for water athletes who frequently underestimate their sweat loss.

Wearable Health Tracking Device Support

Wearable Devices Synchronization:

Used the Plugin.BLE to connect Polar heart rate monitors, Garmin Smart Watches, and Apple Watches via Bluetooth.

Waterproof Data Storage:

An innovative way to store your heart rate variability data while swimming is necessary, as your Bluetooth connection is lost when underwater. Therefore, data is buffered locally, and the data is uploaded when the person exits the water and connects to the internet again.

Metrics Tracked:

Body Weight, Body Fat Percentage, Sleep and Active Calories are part of your physical fitness, while the number of minutes you spend in the pool is used to calculate the amount of resistance you encountered.

Encryption (in transit):

All app data transmitted to the Azure backend is encrypted with TLS 1.3.

Control of user data:

Provides control over deletion of personal information including deletion requests that are compliant with GDPR / CCPA.

Data sharing with third parties:

Limited to analytic purposes only, such as activity from the app and UID for device and user ID. No health information sold.

Users need to have an AquaFit account (either provided free of charge by partner gyms or created through a monthly subscription), and they go through the following steps to set up the account and create their personalized user profile:

• The user onboards into the application where it connects to a wearable and asks them to assign their fitness level (beginner to advanced), and choose their goal (weight loss, gain muscle, or improve their flexibility/yoga).
• Once onboarded, Fitness level & Swimming Goals will be shown under the user's dashboard. It will show the user's workout planned for that day (water or land), how many calories are left in the day and the user's hydration status.
• The user can book their upcoming aquatic classes from a list of available classes with real-time reservation capabilities at all AquaFit locations (Egypt and U.A.E) with a 12-hour cancellation policy.
• The user will earn in excess of 150 badges (a form of gamification) as they consistently work out at the pool, such as a "Mermaid Monday" for working out in the pool four times in a 30-day month.

• Launch Time Frame: 2 months (back-end ASP CORE, MAUI, and DevOps).
• Rating from Store: 4.5 star rating (at launch).
• User Retention: 68% retention rate after 30 days (due to the integrated diet-fitness tracking loop).
• Device Coverage: 95% coverage with tested Bluetooth fitness devices (Polar, Garmin, Fitbit, Apple Watch).

Challenge:

Disconnecting from Bluetooth during water workouts → Solution: added buffered log file with reconnection code.

Future Features:

• AI form analysis using a camera (land-based exercises only).
• Apple Vision Pro companion app with immersive yoga sessions.
• Windows touch mode for Surface devices.

Through AquaFit, we have shown how .NET MAUI can enable one team to build a comprehensive, device-aware fitness solution.

By combining various types of training (aquatic and land) with nutrition planning and syncing with wearable devices, AquaFit provides a complete fitness resource for the modern-day fitness enthusiast who does not want to have to choose between going to the gym, going to the pool, or sitting on their computer.

AquaFit is available today on all platforms: iOS, Android, Windows, and macOS - fitness anywhere!

Live App: