diff --git a/Guibe/Assets.xcassets/AppIcon.appiconset/Contents.json b/Guibe/Assets.xcassets/AppIcon.appiconset/Contents.json
index af9d54c..d5ca7bc 100644
--- a/Guibe/Assets.xcassets/AppIcon.appiconset/Contents.json
+++ b/Guibe/Assets.xcassets/AppIcon.appiconset/Contents.json
@@ -1,28 +1,16 @@
 {
   "images" : [
-	{
+    {
       "size" : "20x20",
-      "idiom": "iphone",
-	  "filename" : "appLogo-20@2x.png",
-      "scale": "2x"
-    },
-	{
-      "size" : "20x20",
-      "idiom": "iphone",
-	  "filename" : "appLogo-20@3x.png",
-      "scale": "3x"
-    },
-	{
-      "size" : "20x20",
-      "idiom": "ipad",
-	  "filename" : "appLogo-20.png",
-      "scale": "1x"
+      "idiom" : "iphone",
+      "filename" : "appLogo-20@2x.png",
+      "scale" : "2x"
     },
     {
       "size" : "20x20",
-      "idiom": "ipad",
-	  "filename" : "appLogo-20@2x.png",
-      "scale": "2x"
+      "idiom" : "iphone",
+      "filename" : "appLogo-20@3x.png",
+      "scale" : "3x"
     },
     {
       "size" : "29x29",
@@ -60,6 +48,18 @@
       "filename" : "appLogo-60@3x.png",
       "scale" : "3x"
     },
+    {
+      "size" : "20x20",
+      "idiom" : "ipad",
+      "filename" : "appLogo-20.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "20x20",
+      "idiom" : "ipad",
+      "filename" : "appLogo-20@2x.png",
+      "scale" : "2x"
+    },
     {
       "size" : "29x29",
       "idiom" : "ipad",
@@ -113,4 +113,4 @@
     "version" : 1,
     "author" : "xcode"
   }
-}
+}
\ No newline at end of file
diff --git a/Guibe/Assets.xcassets/AppIcon.appiconset/logo_mpt-1024.png b/Guibe/Assets.xcassets/AppIcon.appiconset/logo_mpt-1024.png
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diff --git a/Guibe/Assets.xcassets/AppIcon.appiconset/menuBtnImg-76.png b/Guibe/Assets.xcassets/AppIcon.appiconset/menuBtnImg-76.png
deleted file mode 100644
index 3f960c6..0000000
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diff --git a/Guibe/Assets.xcassets/AppIcon.appiconset/menuBtnImg-76@2x.png b/Guibe/Assets.xcassets/AppIcon.appiconset/menuBtnImg-76@2x.png
deleted file mode 100644
index ceee1d8..0000000
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diff --git a/Guibe/Assets.xcassets/AppIcon.appiconset/menuBtnImg-83.5@2x.png b/Guibe/Assets.xcassets/AppIcon.appiconset/menuBtnImg-83.5@2x.png
deleted file mode 100644
index fd89054..0000000
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diff --git a/Guibe/Base.lproj/Main.storyboard b/Guibe/Base.lproj/Main.storyboard
index 28a1eb0..8478f5e 100644
--- a/Guibe/Base.lproj/Main.storyboard
+++ b/Guibe/Base.lproj/Main.storyboard
@@ -1486,6 +1486,22 @@ And that’s all you need to know to follow the vibe!</string>
                                 <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
                                 <state key="normal" title="DO NOT PRESS"/>
                             </button>
+                            <button opaque="NO" contentMode="scaleToFill" fixedFrame="YES" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="YeQ-WQ-n1K">
+                                <rect key="frame" x="89" y="215" width="33" height="30"/>
+                                <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
+                                <state key="normal" title="Dark"/>
+                                <connections>
+                                    <action selector="darkBtnPressed:" destination="FXb-No-u4u" eventType="touchUpInside" id="20Q-Y4-vVN"/>
+                                </connections>
+                            </button>
+                            <button opaque="NO" contentMode="scaleToFill" fixedFrame="YES" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="IyG-gq-Bc5">
+                                <rect key="frame" x="191" y="215" width="35" height="30"/>
+                                <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
+                                <state key="normal" title="Light"/>
+                                <connections>
+                                    <action selector="lightBtnPresssed:" destination="FXb-No-u4u" eventType="touchUpInside" id="4bu-yi-N7Q"/>
+                                </connections>
+                            </button>
                         </subviews>
                         <color key="backgroundColor" white="0.0" alpha="0.0" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                         <viewLayoutGuide key="safeArea" id="3YM-pK-9CO"/>
diff --git a/Guibe/SecretsViewController.swift b/Guibe/SecretsViewController.swift
index f31d5de..66d6983 100644
--- a/Guibe/SecretsViewController.swift
+++ b/Guibe/SecretsViewController.swift
@@ -37,6 +37,29 @@ class SecretsViewController: UIViewController {
     }
     
     
+    @IBAction func darkBtnPressed(_ sender: Any) {
+        if UIApplication.shared.supportsAlternateIcons {
+            if let alternateIconName = UIApplication.shared.alternateIconName {
+                print("current icon is \(alternateIconName), change to primary icon")
+                UIApplication.shared.setAlternateIconName(nil)
+            } else {
+                print("current icon is primary icon, change to alternative icon")
+                UIApplication.shared.setAlternateIconName("ad"){ error in
+                    if let error = error {
+                        print(error.localizedDescription)
+                    } else {
+                        print("Done!")
+                    }
+                }
+            }
+        }
+    }
+    
+    
+    @IBAction func lightBtnPresssed(_ sender: Any) {
+        changeIcon(to: "appLogo-60")
+    }
+    
     
     @IBAction func easterBtnPressed(_ sender: Any) {
         UIView.animate(withDuration: 0.2, animations: {self.view.backgroundColor = .green})
@@ -71,6 +94,24 @@ class SecretsViewController: UIViewController {
         
     }
     
+    
+    func changeIcon(to iconName: String) {
+        // 1
+        guard UIApplication.shared.supportsAlternateIcons else {
+            return
+        }
+        
+        // 2
+        UIApplication.shared.setAlternateIconName(iconName, completionHandler: { (error) in
+            // 3
+            if let error = error {
+                print("App icon failed to change due to \(error.localizedDescription)")
+            } else {
+                print("App icon changed successfully")
+            }
+        })
+    }
+    
 //    defaults.set(0, forKey: "setupDone")
 
 }