diff --git a/app/src/main/java/eu/darken/capod/reaction/core/ReactionHub.kt b/app/src/main/java/eu/darken/capod/reaction/core/ReactionHub.kt
index f1ae1f32..eecd1893 100644
--- a/app/src/main/java/eu/darken/capod/reaction/core/ReactionHub.kt
+++ b/app/src/main/java/eu/darken/capod/reaction/core/ReactionHub.kt
@@ -5,6 +5,7 @@ import eu.darken.capod.common.debug.logging.logTag
 import eu.darken.capod.common.flow.setupCommonEventHandlers
 import eu.darken.capod.reaction.core.autoconnect.AutoConnect
 import eu.darken.capod.reaction.core.playpause.PlayPause
+import eu.darken.capod.reaction.core.popup.PopUpReaction
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.combine
 import javax.inject.Inject
@@ -13,12 +14,14 @@ import javax.inject.Inject
 class ReactionHub @Inject constructor(
     private val playPause: PlayPause,
     private val autoConnect: AutoConnect,
+    private val popUpReaction: PopUpReaction,
 ) {
 
     fun monitor(): Flow<Unit> = combine(
         playPause.monitor(),
-        autoConnect.monitor()
-    ) { _, _ ->
+        autoConnect.monitor(),
+        popUpReaction.monitor()
+    ) { _, _, _ ->
         Unit
     }
         .setupCommonEventHandlers(TAG) { "monitor" }
diff --git a/app/src/main/java/eu/darken/capod/reaction/core/ReactionSettings.kt b/app/src/main/java/eu/darken/capod/reaction/core/ReactionSettings.kt
index eed788b1..fb69654f 100644
--- a/app/src/main/java/eu/darken/capod/reaction/core/ReactionSettings.kt
+++ b/app/src/main/java/eu/darken/capod/reaction/core/ReactionSettings.kt
@@ -42,10 +42,16 @@ class ReactionSettings @Inject constructor(
         moshi
     )
 
+    val showPopUpOnCaseOpen = preferences.createFlowPreference(
+        "reaction.popup.caseopen",
+        false
+    )
+
     override val preferenceDataStore: PreferenceDataStore = PreferenceStoreMapper(
         autoPause,
         autoPlay,
         autoConnect,
         autoConnectCondition,
+        showPopUpOnCaseOpen,
     )
 }
\ No newline at end of file
diff --git a/app/src/main/java/eu/darken/capod/reaction/core/popup/PopUpReaction.kt b/app/src/main/java/eu/darken/capod/reaction/core/popup/PopUpReaction.kt
new file mode 100644
index 00000000..b4079e8f
--- /dev/null
+++ b/app/src/main/java/eu/darken/capod/reaction/core/popup/PopUpReaction.kt
@@ -0,0 +1,57 @@
+package eu.darken.capod.reaction.core.popup
+
+import eu.darken.capod.common.bluetooth.BluetoothManager2
+import eu.darken.capod.common.debug.logging.Logging.Priority.INFO
+import eu.darken.capod.common.debug.logging.Logging.Priority.VERBOSE
+import eu.darken.capod.common.debug.logging.log
+import eu.darken.capod.common.debug.logging.logTag
+import eu.darken.capod.common.flow.setupCommonEventHandlers
+import eu.darken.capod.common.flow.withPrevious
+import eu.darken.capod.main.core.GeneralSettings
+import eu.darken.capod.monitor.core.PodMonitor
+import eu.darken.capod.pods.core.apple.DualApplePods
+import eu.darken.capod.reaction.core.ReactionSettings
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.emptyFlow
+import kotlinx.coroutines.flow.flatMapLatest
+import kotlinx.coroutines.flow.map
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class PopUpReaction @Inject constructor(
+    private val bluetoothManager: BluetoothManager2,
+    private val podMonitor: PodMonitor,
+    private val generalSettings: GeneralSettings,
+    private val reactionSettings: ReactionSettings
+) {
+
+    fun monitor(): Flow<Unit> = reactionSettings.showPopUpOnCaseOpen.flow
+        .flatMapLatest { if (it) podMonitor.mainDevice else emptyFlow() }
+        .withPrevious()
+        .map { (previous, current) ->
+
+            if (previous is DualApplePods? && current is DualApplePods) {
+                log(TAG) { "previous=${previous?.rawCaseLidState}, current=${current.rawCaseLidState}" }
+                log(TAG, VERBOSE) { "previous-id=${previous?.identifier}, current-id=${current.identifier}" }
+
+                val isSameDeviceWithCaseNowOpen =
+                    previous?.identifier == current.identifier && previous.caseLidState != current.caseLidState
+                val isNewDeviceWithJustOpenedCase =
+                    previous?.identifier != current.identifier && previous?.caseLidState != current.caseLidState
+
+                if (isSameDeviceWithCaseNowOpen || isNewDeviceWithJustOpenedCase) {
+                    log(TAG) { "Case lid status changed for monitored device." }
+
+                    if (current.caseLidState == DualApplePods.LidState.OPEN) {
+                        log(TAG, INFO) { "Show popup" }
+                    }
+                }
+            }
+        }
+        .setupCommonEventHandlers(TAG) { "monitor" }
+
+    companion object {
+        private val TAG = logTag("Reaction", "PopUp")
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/res/drawable/ic_baseline_chat_24.xml b/app/src/main/res/drawable/ic_baseline_chat_24.xml
new file mode 100644
index 00000000..91598350
--- /dev/null
+++ b/app/src/main/res/drawable/ic_baseline_chat_24.xml
@@ -0,0 +1,11 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal"
+    android:autoMirrored="true">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M20,2L4,2c-1.1,0 -1.99,0.9 -1.99,2L2,22l4,-4h14c1.1,0 2,-0.9 2,-2L22,4c0,-1.1 -0.9,-2 -2,-2zM6,9h12v2L6,11L6,9zM14,14L6,14v-2h8v2zM18,8L6,8L6,6h12v2z" />
+</vector>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index c0fe60ce..4e12e1be 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -143,4 +143,6 @@
 
     <string name="upgrade_capod_label">Upgrade CAPod</string>
     <string name="upgrade_capod_description">Get additional features and support the developer.</string>
+    <string name="settings_popup_caseopen_label">Show popup</string>
+    <string name="settings_popup_caseopen_description">Show a popup when the device case is opened (experimental).</string>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/xml/preferences_reactions.xml b/app/src/main/res/xml/preferences_reactions.xml
index 6dc3c330..af537ce6 100644
--- a/app/src/main/res/xml/preferences_reactions.xml
+++ b/app/src/main/res/xml/preferences_reactions.xml
@@ -25,4 +25,10 @@
         android:summary="@string/settings_autoconnect_condition_description"
         android:title="@string/settings_autoconnect_condition_label" />
 
+    <CheckBoxPreference
+        android:icon="@drawable/ic_baseline_chat_24"
+        android:key="reaction.popup.caseopen"
+        android:summary="@string/settings_popup_caseopen_description"
+        android:title="@string/settings_popup_caseopen_label" />
+
 </PreferenceScreen>
\ No newline at end of file