IOS App develop using XCode. Need help with the code for the backspace button.

Based on the in-class project, you are requested to implement a new Calculator (similar to Figure b): 1. Design an image and use it as your app icon (10 points) 2. Replace all the button titles on the calculator with appropriate images (20 points) 3. Add "Backspace" button and function so that user can delete his/her latest input in case he/she enters a wrong number. Implement the "Backspace" function (50 points) 4. Make sure appropriate constraints are applied so that your app fits various screen size and orientation (15 points) Based on the in-class project, you are requested to implement a new Calculator (similar to Figure b): 1. Design an image and use it as your app icon (10 points) 2. Replace all the button titles on the calculator with appropriate images (20 points) 3. Add "Backspace" button and function so that user can delete his/her latest input in case he/she enters a wrong number. Implement the "Backspace" function (50 points) 4. Make sure appropriate constraints are applied so that your app fits various screen size and orientation (15 points)