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