I improved the MainView in the app by adding a ZStack for content layering and precise placement of a custom navigation bar at the bottom. The bar, made of a HStack within the ZStack, contains CustomTabItems linked to a 'selectedTab' state variable, enabling smooth view changes. Its design features a custom background color, rounded corners, a subtle shadow, and proper padding. To ensure the bar reaches the bottom screen edge, I used the '.edgesIgnoringSafeArea(.all)' modifier on the ZStack, integrating the navigation bar seamlessly into the app's design and maintaining its visibility and functionality.