Removed not used icon and renamed the application icon properly.

assets/icons.qrc

@@ -1,7 +1,6 @@
 <RCC>
     <qresource prefix="/">
         <file>software-application.png</file>
-        <file>feature.png</file>
         <file>no-picture-taking.png</file>
     </qresource>
 </RCC>

mainwindow.cpp

@@ -33,12 +33,14 @@ MainWindow::MainWindow(QWidget* parent)
   setWindowTitle(QCoreApplication::applicationName() + " [*]");
 
   /// application icon
-  const QString iconString = "://feature.png";
+  const QString iconString = "://software-application.png";
 #ifdef QT_DEBUG
   QPixmap pixmap       = QPixmap(iconString);
   QTransform transform = QTransform();
   transform.rotate(180);
   QPixmap rotated = pixmap.transformed(transform);
+  QIcon appIcon   = QIcon(rotated);
+  qWarning() << "appIcon.availableSizes():" << appIcon.availableSizes();
   setWindowIcon(QIcon(rotated));
 #else
   setWindowIcon(QIcon(iconString));