Overview

Loan EMI & BMI Calculator with AI Assistant is a complete Flutter app that puts loan EMI calculators, FD / RD / SIP planners and health calculators (BMI, BMR, body fat, ideal weight) in one clean app, with an AI finance assistant powered by Groq (Llama 3.3 70B), calculation history and 12 everyday tools. It is built with GetX plus BLoC for the BMI module, translated into 7 languages, and earns from AdMob ads and an optional in-app purchase that removes ads. This is the code base of a live Google Play app, cleaned and documented so you can rebrand it quickly. The Android app is complete; the iOS folder is included but needs setup.

Key features

Loans & investments

• EMI calculator with loan presets (personal, home, car, business, education)
• Result screen with monthly EMI, total interest, total payment and a principal/interest breakdown
• Month-by-month amortization schedule
• FD, RD and SIP calculators with maturity value and returns

Health tools

• BMI calculator with categories, detail screen and a health guide (BLoC)
• BMR (Mifflin–St Jeor), body fat % and ideal weight (Hamwi) calculators

AI finance assistant

• Chat powered by Groq (llama-3.3-70b-versatile) with an EMI-focused system prompt
• Chat history: reopen, delete and clear all
• API key loaded from Firebase Remote Config or a build-time define, never hardcoded; friendly fallback when no key is set

12 everyday tools

• Discount, inflation, percentage, percentage difference and percentage change
• Length, speed, temperature and mass converters, amount in words, age calculator
• Currency converter screen (sample rate, connect your own exchange-rate API)

Experience & engagement

• Bottom navigation: Dashboard, Tools, History and Settings
• 7 languages (English, Spanish, French, German, Portuguese, Hindi, Gujarati) and 7 currency symbols
• Automatic calculation history stored on the device (Hive)
• Language, currency and onboarding flow, rating dialog, in-app update, exit dialog
• Push notifications (FCM + local) with deep links, Firebase Analytics, Crashlytics and Facebook App Events

What's included

• Full Flutter source code (feature folders for EMI, investments, BMI, health calculators, tools, chat, history, premium)
• Android project with custom native-ad layouts and factories
• README with a step-by-step guide: rebranding, Firebase, ads, Groq key, in-app purchase, signing, iOS setup and troubleshooting
• Ad configuration template (assets/mock/ad.json with Google test IDs), a key.properties signing template, LICENSE and CHANGELOG
• All secrets replaced with placeholders; builds out of the box with a debug-key fallback

Tech stack

• Flutter 3.38+ (tested on Flutter 3.47.4), GetX, flutter_bloc, get_it
• Storage: Hive, GetStorage, SharedPreferences
• Firebase: Core, Remote Config, Cloud Messaging, Analytics, Crashlytics
• Ads & IAP: google_mobile_ads 8.x, Meta Audience Network (easy_audience_network), in_app_purchase
• AI: groq_sdk (Llama 3.3 70B)
• Android: AGP 8.11, Kotlin 2.2, Gradle 8.14, Java 17, target/compile SDK 36

Requirements

• Flutter SDK 3.38 or newer, Android Studio or VS Code, JDK 17+
• Your own Firebase project and AdMob account; Meta Audience Network is optional
• A Groq API key for the AI chat (free tier available)
• A Google Play Console account to sell the premium plan

Setup in minutes

• Run flutter pub get and flutterfire configure
• Change the package id, app name and icon
• Add your AdMob App ID and publish the ads_service, Ai_boat_config and premium_config Remote Config parameters
• Create your premium products in Play Console
• Add your keystore to android/key.properties and run flutter build appbundle

Monetization (ads/IAP)

• AdMob formats: App Open (splash and resume), banner, native small and large, interstitial with a frequency cap
• Fallback chain: primary AdMob, then secondary AdMob, then Meta Audience Network, then hide the slot
• Remote control: one Remote Config JSON switches ads on or off and sets every unit ID, the interstitial frequency and native positions
• In-app purchase: monthly and yearly premium products (ids from Remote Config) that remove all ads, with restore purchases

Support & updates

Support is provided through the Aadhya Infotech DevStore: https://www.aadhya-infotech.com/DevStore/contact. Bug-fix updates for this package are published on the DevStore. Please note: the currency converter uses a sample rate, purchase verification is a local stub, premium does not lock the AI chat yet, and iOS needs setup before release; all of this is documented in the README. Health results are general wellness estimates, not medical advice.