This is a fully functional calculator app built from scratch using Flutter. The app handles all the backend logic, including converting infix expressions to postfix and evaluating postfix expressions, all implemented in Dart.

Features
Infix to Postfix Conversion: The app can convert standard infix mathematical expressions to postfix notation for easier computation.
Postfix Expression Evaluation: Once the expression is converted, the app evaluates the postfix expression to give the final result.
Simple and Intuitive UI: A clean and user-friendly interface that makes it easy to perform calculations.