diff --git a/WidgetDestroyer.xcodeproj/project.pbxproj b/WidgetDestroyer.xcodeproj/project.pbxproj
index 309d498..ab7e77f 100644
--- a/WidgetDestroyer.xcodeproj/project.pbxproj
+++ b/WidgetDestroyer.xcodeproj/project.pbxproj
@@ -7,6 +7,8 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		C112618B2B4989530038C671 /* WidgetDetector.swift in Sources */ = {isa = PBXBuildFile; fileRef = C11261842B492F890038C671 /* WidgetDetector.swift */; };
+		C112618D2B498B770038C671 /* UserDefaults+Extension.swift in Sources */ = {isa = PBXBuildFile; fileRef = C112618C2B498B770038C671 /* UserDefaults+Extension.swift */; };
 		C11CF6282B3345BE0040B273 /* WidgetDestroyerApp.swift in Sources */ = {isa = PBXBuildFile; fileRef = C11CF6272B3345BE0040B273 /* WidgetDestroyerApp.swift */; };
 		C11CF62A2B3345BE0040B273 /* ContentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = C11CF6292B3345BE0040B273 /* ContentView.swift */; };
 		C11CF62C2B3345BF0040B273 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = C11CF62B2B3345BF0040B273 /* Assets.xcassets */; };
@@ -44,6 +46,8 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		C11261842B492F890038C671 /* WidgetDetector.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WidgetDetector.swift; sourceTree = "<group>"; };
+		C112618C2B498B770038C671 /* UserDefaults+Extension.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UserDefaults+Extension.swift"; sourceTree = "<group>"; };
 		C11CF6242B3345BE0040B273 /* WidgetDestroyer.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = WidgetDestroyer.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		C11CF6272B3345BE0040B273 /* WidgetDestroyerApp.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WidgetDestroyerApp.swift; sourceTree = "<group>"; };
 		C11CF6292B3345BE0040B273 /* ContentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentView.swift; sourceTree = "<group>"; };
@@ -102,6 +106,8 @@
 			children = (
 				C11CF6272B3345BE0040B273 /* WidgetDestroyerApp.swift */,
 				C11CF6292B3345BE0040B273 /* ContentView.swift */,
+				C11261842B492F890038C671 /* WidgetDetector.swift */,
+				C112618C2B498B770038C671 /* UserDefaults+Extension.swift */,
 				C11CF62B2B3345BF0040B273 /* Assets.xcassets */,
 			);
 			path = WidgetDestroyer;
@@ -228,7 +234,9 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				C112618B2B4989530038C671 /* WidgetDetector.swift in Sources */,
 				C11CF62A2B3345BE0040B273 /* ContentView.swift in Sources */,
+				C112618D2B498B770038C671 /* UserDefaults+Extension.swift in Sources */,
 				C11CF6282B3345BE0040B273 /* WidgetDestroyerApp.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
diff --git a/WidgetDestroyer/ContentView.swift b/WidgetDestroyer/ContentView.swift
index d6038e7..0a609bc 100644
--- a/WidgetDestroyer/ContentView.swift
+++ b/WidgetDestroyer/ContentView.swift
@@ -10,10 +10,20 @@ import WidgetKit
 
 struct ContentView: View {
 
+  @State private var widgetsInUse: [WidgetFamily] = []
+
   @Environment(\.scenePhase) private var scenePhase
 
   var body: some View {
     VStack {
+      GroupBox("Widgets in use") {
+        ForEach(widgetsInUse, id: \.self) { widget in
+          Text(widget.description)
+            .font(.body)
+        }
+      }
+      .padding()
+
       Image(systemName: "arrow.clockwise")
         .imageScale(.large)
 
@@ -21,9 +31,15 @@ struct ContentView: View {
     }
     .font(.largeTitle)
     .onChange(of: scenePhase) { _, newPhase in
-      if newPhase == .background {
+      if newPhase == .active {
+        WidgetDetector.shared.detect() // ✅
+        // just to display the current widgets
+        DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
+          widgetsInUse = Array(UserDefaults.standard.get(\.widgetsInUse))
+            .sorted(by: { $0.description.count < $1.description.count })
+        }
+      } else if newPhase == .background {
         WidgetCenter.shared.reloadAllTimelines()
-        print("♻️ Widget reload")
       }
     }
   }
diff --git a/WidgetDestroyer/UserDefaults+Extension.swift b/WidgetDestroyer/UserDefaults+Extension.swift
new file mode 100644
index 0000000..3d00648
--- /dev/null
+++ b/WidgetDestroyer/UserDefaults+Extension.swift
@@ -0,0 +1,34 @@
+//
+//  UserDefaults+Extension.swift
+//  WidgetDestroyer
+//
+//  Created by 유재호 on 1/6/24.
+//
+
+import WidgetKit
+
+extension WidgetFamily: Codable { }
+
+extension UserDefaults {
+
+  struct MyData: Codable {
+    var widgetsInUse = Set<WidgetFamily>()
+  }
+
+  func set<T>(_ keyPath: WritableKeyPath<MyData, T>, _ value: T) {
+    var myData = MyData()
+    myData[keyPath: keyPath] = value
+    let asData = try? JSONEncoder().encode(myData)
+    set(asData, forKey: "MyData")
+  }
+
+  func get<T>(_ keyPath: KeyPath<MyData, T>) -> T {
+    guard
+      let asData = data(forKey: "MyData"),
+      let myData = try? JSONDecoder().decode(MyData.self, from: asData)
+    else {
+      return MyData()[keyPath: keyPath] // returns default value
+    }
+    return myData[keyPath: keyPath]
+  }
+}
diff --git a/WidgetDestroyer/WidgetDetector.swift b/WidgetDestroyer/WidgetDetector.swift
new file mode 100644
index 0000000..3acccd2
--- /dev/null
+++ b/WidgetDestroyer/WidgetDetector.swift
@@ -0,0 +1,54 @@
+//
+//  WidgetDetector.swift
+//  NumberWidgetExtension
+//
+//  Created by 유재호 on 1/6/24.
+//
+
+import WidgetKit
+
+final class WidgetDetector {
+
+  /// Singleton instance of WidgetDetector
+  static let shared = WidgetDetector()
+
+  private init() { }
+
+  func detect() {
+    WidgetCenter.shared.getCurrentConfigurations { result in
+      if case .success(let widgetInfo) = result {
+        self.diff(widgetInfo)
+      }
+    }
+  }
+
+  private func diff(_ newValue: [WidgetInfo]) {
+    let cachedWidgetsInUse = UserDefaults.standard.get(\.widgetsInUse)
+    let newWidgetsInUse = Set(newValue.map(\.family))
+
+    guard newWidgetsInUse != cachedWidgetsInUse else {
+      return // ignores if the same
+    }
+
+    let addedWidgets = newWidgetsInUse.subtracting(cachedWidgetsInUse)
+    let removedWidgets = cachedWidgetsInUse.subtracting(newWidgetsInUse)
+
+    for added in addedWidgets {
+      didAddWidget(family: added)
+    }
+
+    for removed in removedWidgets {
+      didRemoveWidget(family: removed)
+    }
+
+    UserDefaults.standard.set(\.widgetsInUse, newWidgetsInUse)
+  }
+
+  private func didAddWidget(family: WidgetFamily) {
+    print("🟢\(family) widget added!")
+  }
+
+  private func didRemoveWidget(family: WidgetFamily) {
+    print("🔴\(family) widget removed!")
+  }
+}