Sticker Chat 
Sticker chat is a messaging application built using Flutter, Stream, and Rive. It allows users to send and receive messages in real-time in just a few lines of code.
The project is broken up into a few key folders 
- lib: Directory containing all Flutter/Dart code.
- app: Application setup and configuration
- models: Domain model used throughout the codebase
- screens: UI widgets displayed to the user. This directory also contains the subfolder “desktop,” which holds code for devices with large screen sizes.
- utils: Helper functions and extensions
- widgets: Reusable pieces of UI used by both the desktop and mobile layouts.
Animations sourced from Rive’s community center. Check out their website for awesome animated assets.
Download Sticker Chat app source code on GitHub
Provides the list of the opensource Flutter apps collection with GitHub repository.