diff --git a/Projects/App/iOS/Sources/Application/OndoseeIOSApp.swift b/Projects/App/iOS/Sources/Application/OndoseeIOSApp.swift
index 7bbedc5..c1d482f 100644
--- a/Projects/App/iOS/Sources/Application/OndoseeIOSApp.swift
+++ b/Projects/App/iOS/Sources/Application/OndoseeIOSApp.swift
@@ -1,10 +1,18 @@
 import SwiftUI
+import RootFeature
 
 @main
 struct OndoseeIOSApp: App {
     var body: some Scene {
         WindowGroup {
-            EmptyView()
+            RootView(
+                store: .init(
+                    initialState: .init(),
+                    reducer: {
+                        RootCore()
+                    }
+                )
+            )
         }
     }
 }
diff --git a/Projects/Feature/MainTabFeature/Sources/MainTabCore.swift b/Projects/Feature/MainTabFeature/Sources/MainTabCore.swift
index c7114f5..3c8ce04 100644
--- a/Projects/Feature/MainTabFeature/Sources/MainTabCore.swift
+++ b/Projects/Feature/MainTabFeature/Sources/MainTabCore.swift
@@ -6,11 +6,11 @@ import WeeklyForecastFeature
 public struct MainTabCore: Reducer {
     public init() {}
     public struct State: Equatable {
-        var mainCore: MainCore.State
-        var weeklyCore: WeeklyForecastCore.State
-        var settingCore: SettingCore.State
-
-        public init() { self = .init() }
+        var tabFlow: TabFlow = .main
+        var mainCore = MainCore.State()
+        var weeklyCore = WeeklyForecastCore.State()
+        var settingCore = SettingCore.State()
+        public init() {}
     }
 
     public enum Action {
@@ -23,10 +23,13 @@ public struct MainTabCore: Reducer {
     public var body: some Reducer<State, Action> {
         Reduce { state, action in
             switch action {
+            case let .changeTabFlow(flow):
+                state.tabFlow = flow
+                return .none
+
             default:
                 return .none
             }
-            return .none
         }
     }
 }
diff --git a/Projects/Feature/MainTabFeature/Sources/MainTabView.swift b/Projects/Feature/MainTabFeature/Sources/MainTabView.swift
index ca341c8..ac358dd 100644
--- a/Projects/Feature/MainTabFeature/Sources/MainTabView.swift
+++ b/Projects/Feature/MainTabFeature/Sources/MainTabView.swift
@@ -10,11 +10,16 @@ public struct MainTabView: View {
 
     public init(store: StoreOf<MainTabCore>) {
         self.store = store
+        UITabBar.appearance().backgroundColor = .clear
+        UITabBar.appearance().scrollEdgeAppearance = .init()
     }
 
     public var body: some View {
         WithViewStore(self.store, observe: { $0 }) { viewStore in
-            TabView {
+            TabView(selection: viewStore.binding(
+                    get: \.tabFlow,
+                    send: MainTabCore.Action.changeTabFlow)
+            ) {
                 MainView(store: store.scope(
                     state: \.mainCore,
                     action: MainTabCore.Action.mainCore)
@@ -50,6 +55,7 @@ public struct MainTabView: View {
                         .font(.medium(.system, size: .text3))
                 }
             }
+            .accentColor(.ondosee(.system(.selected)))
         }
     }
 }
diff --git a/Projects/Feature/MainTabFeature/Sources/Sources.swift b/Projects/Feature/MainTabFeature/Sources/Sources.swift
deleted file mode 100644
index 50ff8a0..0000000
--- a/Projects/Feature/MainTabFeature/Sources/Sources.swift
+++ /dev/null
@@ -1,2 +0,0 @@
-import SwiftUI
-
diff --git a/Projects/Feature/RootFeature/Project.swift b/Projects/Feature/RootFeature/Project.swift
new file mode 100644
index 0000000..de1cb42
--- /dev/null
+++ b/Projects/Feature/RootFeature/Project.swift
@@ -0,0 +1,16 @@
+import DependencyPlugin
+import ProjectDescription
+import ProjectDescriptionHelpers
+
+let project = Project.module(
+    name: ModulePaths.Feature.RootFeature.rawValue,
+    targets: [
+        .implements(module: .feature(.RootFeature), dependencies: [
+            .feature(target: .BaseFeature),
+            .feature(target: .MainTabFeature)
+        ]),
+        .tests(module: .feature(.RootFeature), dependencies: [
+            .feature(target: .RootFeature)
+        ])
+    ]
+)
diff --git a/Projects/Feature/RootFeature/Sources/RootCore.swift b/Projects/Feature/RootFeature/Sources/RootCore.swift
new file mode 100644
index 0000000..59fe1ed
--- /dev/null
+++ b/Projects/Feature/RootFeature/Sources/RootCore.swift
@@ -0,0 +1,26 @@
+import ComposableArchitecture
+import Foundation
+import MainTabFeature
+
+public struct RootCore: Reducer {
+    public init() {}
+    public enum State: Equatable {
+        case mainTab(MainTabCore.State)
+
+        public init() { self = .mainTab(.init()) }
+    }
+
+    public enum Action {
+        case mainTabCore(MainTabCore.Action)
+    }
+
+    public var body: some Reducer<State, Action> {
+        Reduce { state, action in
+            switch action {
+            case .mainTabCore:
+                state = .mainTab(.init())
+                return .none
+            }
+        }
+    }
+}
diff --git a/Projects/Feature/RootFeature/Sources/RootView.swift b/Projects/Feature/RootFeature/Sources/RootView.swift
new file mode 100644
index 0000000..68fd5c7
--- /dev/null
+++ b/Projects/Feature/RootFeature/Sources/RootView.swift
@@ -0,0 +1,22 @@
+import ComposableArchitecture
+import SwiftUI
+import MainTabFeature
+
+public struct RootView: View {
+    private let store: StoreOf<RootCore>
+
+    public init(store: StoreOf<RootCore>) {
+        self.store = store
+    }
+
+    public var body: some View {
+        SwitchStore(store) {
+            switch $0 {
+            case .mainTab:
+                CaseLet(/RootCore.State.mainTab, action: RootCore.Action.mainTabCore) { store in
+                    MainTabView(store: store)
+                }
+            }
+        }
+    }
+}
diff --git a/Projects/Feature/RootFeature/Tests/Tests.swift b/Projects/Feature/RootFeature/Tests/Tests.swift
new file mode 100644
index 0000000..9f44cbf
--- /dev/null
+++ b/Projects/Feature/RootFeature/Tests/Tests.swift
@@ -0,0 +1 @@
+// This is For Tuist
diff --git a/Projects/Feature/SettingFeature/Sources/SettingCore.swift b/Projects/Feature/SettingFeature/Sources/SettingCore.swift
index b348de8..5ea1f3b 100644
--- a/Projects/Feature/SettingFeature/Sources/SettingCore.swift
+++ b/Projects/Feature/SettingFeature/Sources/SettingCore.swift
@@ -4,7 +4,7 @@ import Foundation
 public struct SettingCore: Reducer {
     public init() {}
     public struct State: Equatable {
-        
+        public init() {}
     }
 
     public enum Action: Equatable {
diff --git a/Projects/Feature/WeeklyForecastFeature/Sources/WeeklyForecastCore.swift b/Projects/Feature/WeeklyForecastFeature/Sources/WeeklyForecastCore.swift
index 038f697..977d559 100644
--- a/Projects/Feature/WeeklyForecastFeature/Sources/WeeklyForecastCore.swift
+++ b/Projects/Feature/WeeklyForecastFeature/Sources/WeeklyForecastCore.swift
@@ -4,14 +4,12 @@ import Foundation
 public struct WeeklyForecastCore: Reducer {
     public init() {}
     public struct State: Equatable {
-        
+        public init() {}
     }
 
     public enum Action: Equatable {
-        
     }
 
-    public func reduce(into state: inout State, action: Action) -> Effect<Action> {
-        
+    public func reduce(into state: inout State, action: Action) -> Effect<Action> { 
     }
 }
diff --git a/Projects/UserInterface/DesignSystem/Resources/Colors/System.xcassets/Selected.colorset/Contents.json b/Projects/UserInterface/DesignSystem/Resources/Colors/System.xcassets/Selected.colorset/Contents.json
new file mode 100644
index 0000000..0c600f9
--- /dev/null
+++ b/Projects/UserInterface/DesignSystem/Resources/Colors/System.xcassets/Selected.colorset/Contents.json
@@ -0,0 +1,38 @@
+{
+  "colors" : [
+    {
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0x00",
+          "green" : "0x00",
+          "red" : "0x00"
+        }
+      },
+      "idiom" : "universal"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0xFF",
+          "green" : "0xFF",
+          "red" : "0xFF"
+        }
+      },
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}
diff --git a/Projects/UserInterface/DesignSystem/Sources/Color/ODColorSystem+System.swift b/Projects/UserInterface/DesignSystem/Sources/Color/ODColorSystem+System.swift
index cd9c6b1..80417e2 100644
--- a/Projects/UserInterface/DesignSystem/Sources/Color/ODColorSystem+System.swift
+++ b/Projects/UserInterface/DesignSystem/Sources/Color/ODColorSystem+System.swift
@@ -7,6 +7,7 @@ public extension Color.OndoseeColorSystem {
         case secondary
         case tertiary
         case warning
+        case selected
     }
 }
 
@@ -18,6 +19,7 @@ public extension Color.OndoseeColorSystem.System {
         case .secondary: return DesignSystemAsset.System.secondary.swiftUIColor
         case .tertiary: return DesignSystemAsset.System.tertiary.swiftUIColor
         case .warning: return DesignSystemAsset.System.warning.swiftUIColor
+        case .selected: return DesignSystemAsset.System.selected.swiftUIColor
         }
     }
 }