hello, could you introduce a “close app button” 
, like positioning it after Backup Button other than closing app from the main window. thanks
Why?
What mainstream application has such a feature? Spreadsheet apps do not. Word processors do not. Internet browsers do not. You close a window or quit an application with features of your operating system, just as with Manager.
I concur. Use the operating system’s control functions to open/close windows or quit applications. This makes for a consistent user experience using many programs on your computer. I cannot see what purpose an internal close button would achieve. Either you want the application opened or closed. If you want to go to a new business, just click on business.