The class variable property (ActiveFile) is used to determine when a file has been opened, so when the user wants to use the Save function, we will know whether to save to an existing file or not. The TextBox_KeyDown subroutine is to determine when the Tab key is pressed. If it is, we want to add a tab within the RichEditBox as if the user did it. By default, focus is moved from the RichEditBox to the next object in the application. The e.Handled line is to tell Windows 8 we have dealt with the event and any default action should not be executed. The third line within the If statement is to get the text in the RichEditBox that is currently selected (hence, Selecction.GetText()) and put it in the SelectionText variable. Then, on the last line within the If statement, add a tab character (vbTab does this) and the SelectionText afterwards. The OpenButton_Click subroutine is invoked when the "Open" button is clicked. As you can see, the If statement is used to check whether the application view state is currently set to "snapped". If you recall, the reason I have this check in place is because an open file dialogue will be displayed, and it cannot be displayed while the application is snapped. It either needs to be filled (2/3) or full screen. If the Unsnap is unsuccessful, we exit the subroutine; otherwise, we execute the ShowOpenFilePicker() method. The SaveButton_Click subroutine similarly checks whether the application view state is