How we developed a calorie-counting mobile app that connects to an external weighing scale via IoT?

The app's concept came from one of our previous clients for whom we developed a CRM for their computer repair business.

They wanted to build an app to show the number of calories per 100 grams serving in any food product. The goal was to create a powerful tool for health-conscious people who want to track their food habits, make incremental changes to their dietary habits to get fit, lose weight or achieve a fitness goal.

We helped Weight Plate launch an Android and iPhone app that can be connected to a weighing scale via Bluetooth to track total calorie intake and provide a host of powerful features to help anyone adopt a fit lifestyle.

We began working on the project in 2017 when React Native had fewer libraries to connect hardware devices to a mobile app.

At the same time, the app required a massive database of dietary information, including the number of calories, nutritional information, and dietary benefits. There was no public database to gather such data.

On top of everything, the client needed a feature that would help people practice caloric deficit/increase based on their goal of reducing/increasing weight.

Additional feature requests included finding a way to track daily activities like cycling, swimming, walking, etc., to help people see their daily calorie intake and become fit/achieve their goals accordingly.

All in all, proprietary health information, limited libraries to connect with hardware, and a bunch load of features made the project tricky even before starting.

Our team took the challenge to build an app that connects to an external weighing scale via BlueTooth. A BlueTooth library was used to communicate with an external device (weighing scale). The team took time to understand the read/write format for external data. A dedicated solution was developed to ensure seamless data transfer between the weighing scale and the mobile app.

The app would allow users to create their profile, add their vitals and start regulating their meals by weighing the foods and getting dietary information in real-time.

The app connects to Google Health & Apple Health SDK to capture activity data and provide detailed activity reports on calorie burns and the number of steps/exercise they need to achieve their fitness goals.

A proprietary formula was devised based on BMI that would factor in user’s age, goal, gender, and daily food/exercise habits to tell them what they need to do (in terms of calorie deficit/exercising) to achieve their goals.

Nutritional data about food products were sourced from publicly available sources using a crawling script that would update the data daily for the most accurate depiction of the number of calories in each meal.

Apart from the fitness features, the following features were added for enhanced user experience:

• Secure login via social profiles like Facebook, Twitter & Instagram
• Google Fit and Apple Health app connectivity with real-time data sync
• Daily food diary for breakfast, lunch, dinner, and snacks intake
• Food wastage log to understand your food habits
• Health tips and guides for general information on maintaining a healthy lifestyle
• Prompt-based questionnaire to help people reach their fitness goals week-on-week