Flutter CA App Manager

I want a cross-platform Flutter application that acts as my digital “CA Diary,” focused exclusively on managing client information. The core flow should let me open the app, find any client instantly, and see everything relevant to our work together in one place.

Key functional areas I must have:

• Client profiles – basic details, PAN/GST numbers, contact data and custom tags.
• Document storage – upload, view and categorize files against each client. PDF and image formats are enough for now.
• Interaction history – a simple timeline showing calls, emails or in-person meetings so I can track what happened and when.
• GST & IT Return modules – record returns filed, due dates and status.
• Service tracking – log any other professional services I provide plus their current stage.
• Payment reminders – set an amount, due date and an automatic push notification or email reminder.

A clean, tabbed UI works best for me; it should remain responsive on both Android and iOS. All data needs to stay secure—local encryption or a trusted cloud backend is fine as long as you outline the approach.

Acceptance criteria
1. I can add, edit and delete a client within three taps.
2. Uploading a document shows the file under that client instantly.
3. Interaction history auto-sorts by newest first.
4. GST and IT Return screens calculate next due dates automatically.
5. Payment reminders trigger at the scheduled time even if the app is closed.
6. Entire project builds and runs without errors via a single Flutter command.

Share a brief overview of the database schema you plan to use and the third-party packages (if any) you’ll rely on—especially for secure storage and notifications. Once we agree, the deliverable is the complete Flutter project with well-commented code and a short setup guide so I can compile it locally.