Rebuild Workflow Cost Calculator in Flutter

PROJECT SPECIFICATION – WWCC (Worksite Workflow Cost Calculator) – Full Rebuild in Flutter

1. Project Overview
HERM Logic requires a complete rebuild of the existing WWCC – Worksite Workflow Cost Calculator mobile application.
The current version was developed in FlutterFlow and has been fully tested on Android. The UI/UX, workflows, calculations, and PDF‑email reporting all function correctly.

The objective of this project is to rebuild the entire application natively in Flutter, preserving all existing functionality and design, while improving performance, maintainability, and ensuring full compatibility with both Android and iOS.

This rebuild will be performed by the same freelancer who developed the FlutterFlow version.

2. Purpose of the Rebuild
FlutterFlow is suitable for prototyping, but HERM requires a production‑grade Flutter codebase.

The rebuilt app must be:
- Fully native Flutter (no FlutterFlow dependencies)
- Optimized for speed, reliability, and scalability
- Ready for App Store & Google Play deployment
- Maintainable for future feature expansion (multi‑language, industry modules, analytics, user accounts, etc.)

3. Scope of Work
3.1 Rebuild All Existing Screens (1:1 Replication)
The freelancer will rebuild all screens exactly as they appear in the current app, including:
- Splash / Welcome Page
- Code Authenticator Page
- Language Selector
- Industry Selector
- Labor Cost Input Page
- Work Start Delay Input Page
- Supplier Delivery Cost Input Page
- Financial Impact Summary Page
- PDF Report Sender Page
- Thank You / Completion Page
((Screenshots have been provided for reference.))

3.2 Functional Requirements
A. Input Modules
Each module must replicate existing logic:
(1) Labor Cost Calculator
- Inputs: Work hours, crew size, hourly rate, jobs per month
- Output: Monthly labor cost
- Formula: identical to current app

(2) Work Start Delay Calculator
- Inputs: delay hours, crew size, hourly rate, jobs per month
- Output: monthly delay cost
- Formula: identical to current app

(3) Supplier Delivery Cost Calculator
Inputs: material cost, delivery charge, markup %, jobs per month
- Output: monthly supplier cost
- Formula: identical to current app
All formulas and logic must be ported exactly from the FlutterFlow version.

B. Financial Impact Summary
Rebuild the full summary engine:
- Annual cost breakdown
- Annual savings breakdown
- ROI calculation
- Payback period
- Pie charts (Flutter chart library)
- Summary text blocks
- Dynamic values based on user inputs
The summary must match the existing visual design and numerical outputs.

C. PDF Generation & Email Sending
The current app successfully:
- Generates a PDF report
- Sends it via email to sender + receiver
- Uses the existing report layout (provided in screenshots)

The Flutter rebuild must:
- Recreate the same PDF layout
- Use a Flutter PDF library (e.g., pdf + printing)
- Support sending via email (SMTP or API-based)
- Ensure compatibility with iOS mail clients

D. Multi‑Language Support
Current languages:
- English
- Spanish
- Portuguese

The rebuild must include:
- Same language selector
- Same translations
- Same industry selector logic

E. UI/UX Requirements
- Rebuild the UI exactly as shown in screenshots
- Maintain all animations, transitions, and layout behavior
- Ensure responsive design for various screen sizes
- Ensure identical “look and feel” to the FlutterFlow version

3.3 Technical Requirements
- Codebase must be 100% Flutter (Dart)
- No FlutterFlow dependencies
- Clean architecture (MVVM or similar)
- Modular structure for future expansion
- Full iOS + Android compatibility
- Integration with email/PDF libraries
- Use of best‑practice state management (Provider, Riverpod, or Bloc)

4. Deliverables
A. Complete Flutter Source Code
- Fully functioning app
- All modules rebuilt
- All screens implemented
- All calculations working
- All PDF generation working
- All email sending working
- All languages implemented
- All charts implemented
- All UI/UX matched to original

B. iOS & Android Build Files
- Android APK + AAB
- iOS IPA (TestFlight-ready)

C. Documentation
- Setup instructions
- Build instructions
- Code architecture overview
- Library list
- Notes for future expansion

5. Testing Requirements
The freelancer must perform:
- Full Android testing
- Full iOS testing (simulator + physical device if available)
- Validation of all calculations
- Validation of all PDF outputs
- Validation of email sending
- Validation of multi-language functionality
- Validation of charts and summary logic

6. Project Timeline
- Total Duration: 3–4 weeks
- Milestones:
: Week 1 – UI/UX rebuild
: Week 2 – Logic + calculations + charts
: Week 3 – PDF + email + multi-language
: Week 4 – Testing + final delivery

7. Acceptance Criteria
The project is considered complete when:
- The Flutter app matches the FlutterFlow version 1:1
- All calculations produce identical results
- All screens match the provided screenshots
- PDF reports match the existing layout
- Email sending works on both Android and iOS
- The app runs smoothly on both platforms
- The codebase is clean, modular, and maintainable

8. Intellectual Property
All code, assets, and deliverables become the exclusive property of HERM Logic LLC; HERM Group Limited; and John C. Musster upon payment.

9. Freelancer Requirements
- Must have proven Flutter experience
- Must understand FlutterFlow → Flutter migration
- Must deliver clean, production‑ready code
- Must be available for communication during the project
- Must be able to test on both Android and iOS

10. Summary
This project is a full rebuild of the existing WWCC app from FlutterFlow into native Flutter, preserving all functionality, UI/UX, calculations, and PDF reporting.
The freelancer already knows the app, making this a straightforward rebuild with clear requirements and deliverables.