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InterFITAI: AI Fitness
Studio Kelcy
InterFIT AI: Personalised Fitness and Nutrition
InterFIT AI is an AI-powered fitness and nutrition app that creates personalised workout and meal plans based on each user’s goals, preferences and individual profile.
Studio Kelcy worked across the complete app journey—from branding and UI/UX design through to FlutterFlow development, AI integration and launch.
Project Overview
Services
Branding, app design, FlutterFlow development and launch
Platforms
iOS and Android
Technology
FlutterFlow, Firebase, OpenAI and RevenueCat
Industry
Fitness and wellness
Project Type
New app design and development
The Brief
The vision for InterFIT AI was to create a more personalised way for people to plan their fitness and nutrition.
Instead of providing the same programs to every user, the app needed to consider information such as their experience, goals, available equipment, food preferences and dietary requirements.
AI would then use this information to generate personalised workouts, meal plans and answers to fitness-related questions.
The client required support across the full project, including the visual identity, app experience, technical build and launch.
Phase 1: Design
Creating the Brand
The first stage involved creating a visual direction that would position InterFIT AI as a modern, intelligent and approachable fitness platform.
Studio Kelcy developed the:
Logo
App icon
Colour palette
Typography
Supporting visual style
App interface
The identity was then applied consistently throughout the mobile experience and supporting launch materials.
Planning the User Experience
The app needed to collect enough information to create useful recommendations without making onboarding feel unnecessarily complicated.
The experience was structured around a clear journey:
Create a personal profile
Select fitness goals and preferences
Add available equipment and experience
Add dietary preferences and requirements
Generate a personalised plan
Save and revisit previous plans
Ask the AI trainer follow-up questions
This initial planning established what information the AI required and how users would interact with the generated results.
Designing the Core Features
The interface was designed around four central tools:
Personalised macro calculator
AI-generated workout plans
AI-generated meal plans
InterFIT AI Trainer
Each tool follows a guided process, helping users provide the relevant information before displaying their personalised results.
The design also needed to make detailed workout and nutrition content easy to read on a mobile screen.
Phase 2: Build
FlutterFlow and Firebase Development
Once the designs were approved, the app was built in FlutterFlow and connected to Firebase.
Firebase manages user accounts, personal profiles, saved information and generation history. The database was structured so users could return to previously created plans without generating the same content again.
The build included:
Firebase authentication
User profiles
Dynamic forms
AI integrations
Generated content
Saved plan history
Subscription access
Responsive mobile layouts
Personalised Profile
Users begin by creating a profile containing the information needed to personalise their experience.
Depending on the tool they are using, this may include:
Fitness goals
Experience level
Preferred training style
Target muscle groups
Available equipment
Exercise considerations
Food preferences
Dietary requirements and allergies
This information is securely connected to the user’s account and used to inform future generations.
AI-Generated Workouts
InterFIT AI generates personalised workout plans using the user’s profile, goals, experience and available equipment.
Users can also specify the areas they would like to train and note any exercise considerations that may affect their program.
The generated plan is presented in a clear format containing exercises and supporting instructions. Plans can be saved so users can return to them later.
AI-Generated Meal Plans
The meal-plan generator combines profile information with the user’s food preferences and dietary requirements.
Users can identify:
Preferred foods
Foods they would like excluded
Allergies or dietary restrictions
Supplements they use
Other relevant preferences
InterFIT AI then creates a meal plan tailored to the information provided. Completed plans are stored within the user’s history.
Macro Calculator
The personalised macro calculator uses the user’s profile, general activity and goals to create suggested daily nutrition targets.
The results are clearly displayed within the app and can be used to inform the AI meal-plan generator.
InterFIT AI Trainer
The AI Trainer gives users a conversational way to ask questions relating to their existing plans.
Users can ask for:
Alternative exercises
Adjustments to a workout
Food substitutions
Changes to a meal plan
General explanations about their generated content
This creates a more flexible experience, allowing a plan to adapt as a user’s circumstances or preferences change.
History and Saved Plans
Generated workouts, meal plans and previous activity are stored within the user’s history.
This allows users to revisit their earlier plans and reduces the need to repeat the setup process every time they open the app.
Subscription Access
RevenueCat was integrated to manage paid access.
Subscription status determines which tools and generations are available to each user, with purchase and restore functionality connected across the app experience.
Key Functionality
User accounts and personalised profiles
AI chat assistant
AI-generated workout plans
AI-generated meal plans
Personalised macro calculator
BMI calculator
Dietary preferences and allergy considerations
Equipment and training preferences
Exercise substitutions
Saved plans and generation history
Subscription access
Purchase restoration
Firebase database
OpenAI integration
Phase 3: Launch
Testing and Preparation
Once the build was complete, the app moved through final testing and launch preparation.
Studio Kelcy supported:
Functional testing
AI-response testing
User-flow testing
Subscription configuration
Firebase production setup
App icon and launch-screen preparation
Store listing requirements
iOS and Android deployment
Final launch support
Particular attention was given to the information sent to the AI and how generated content was formatted when returned to the app.
App Store Launch
The completed app was prepared and submitted for release across the Apple App Store and Google Play.
This included configuring the production environment, connecting store products and ensuring the app met the technical requirements for release.
The Outcome
InterFIT AI was brought from an initial concept to a complete AI-powered mobile product.
The finished app combines profile information, guided inputs and AI generation to create a personalised fitness and nutrition experience. Users can generate workouts and meal plans, ask follow-up questions and return to their saved history within one connected platform.
For the client, the project created a scalable digital product with subscriptions, user accounts and AI features built into its core experience.
Explore the Project
Website
https://interfitai.com/
Download on the App Store
https://apps.apple.com/au/app/interfitai/id6529524102
Get it on Google Play
https://play.google.com/store/apps/details?id=com.interfitai.app&hl=en_AU
Have an App Idea?
Studio Kelcy helps founders and businesses design, build and launch thoughtful digital products with FlutterFlow.
From early planning and UI/UX design through to development, testing and store launch, Studio Kelcy can help bring your app idea to life.
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Posted Jun 30, 2025
An AI fitness app that revolutionises your training. The ultimate personalised fitness and nutrition app, tailored specifically to your needs.
Likes
6
Views
292
Timeline
Jul 30, 2023 - Feb 27, 2025
