Flutter-Based PDF Annotation App

Project: PDF Annotation App (Flutter – Android & iPad)

I need a Flutter mobile app that works on:
Android mobile phones
Android tablets
iPad
The app should allow users to open a PDF from local storage, write/draw on it, and save a new annotated PDF to a different folder.
Main Features Required
Open PDF
User selects a PDF from device storage
Drawing & Annotation Tools
Pen with colors: Black, Blue, Red, Green
Pencil tool
Crayon tool with 12 common colors
Eraser tool
Adjustable stroke size
User Actions
Draw/write directly on the PDF pages
Undo / Redo
Clear page
Save Output
Save the edited PDF as a new file
Original PDF must remain unchanged
User should be able to choose/save to a different path
Deliverables
Complete Flutter source code
Working APK file (installable on Android phone)
App should be tested on Android mobile & tablet
iPad compatibility required
Technology Preference
Flutter only
Clean UI suitable for tablets and mobiles
No backend required (fully offline app)
Extra (Good to Have)
Smooth pen writing (low lag)
Proper scaling for large PDFs
Simple and clean UI