diff --git a/app/src/main/java/io/timelimit/android/ui/manage/child/category/Adapter.kt b/app/src/main/java/io/timelimit/android/ui/manage/child/category/Adapter.kt
index 3b52b5d..40d4313 100644
--- a/app/src/main/java/io/timelimit/android/ui/manage/child/category/Adapter.kt
+++ b/app/src/main/java/io/timelimit/android/ui/manage/child/category/Adapter.kt
@@ -31,6 +31,7 @@ class Adapter: RecyclerView.Adapter<ViewHolder>() {
         private const val TYPE_ITEM = 0
         private const val TYPE_ADD = 1
         private const val TYPE_INTRO = 2
+        private const val TYPE_MANIPULATION_WARNING = 3
     }
 
     var categories: List<ManageChildCategoriesListItem>? by Delegates.observable(null as List<ManageChildCategoriesListItem>?) { _, _, _ -> notifyDataSetChanged() }
@@ -48,6 +49,7 @@ class Adapter: RecyclerView.Adapter<ViewHolder>() {
             is CategoryItem -> item.category.id.hashCode()
             CreateCategoryItem -> item.hashCode()
             CategoriesIntroductionHeader -> item.hashCode()
+            ManipulationWarningCategoryItem -> item.hashCode()
         }.toLong()
     }
 
@@ -55,6 +57,7 @@ class Adapter: RecyclerView.Adapter<ViewHolder>() {
         is CategoryItem -> TYPE_ITEM
         CreateCategoryItem -> TYPE_ADD
         CategoriesIntroductionHeader -> TYPE_INTRO
+        ManipulationWarningCategoryItem -> TYPE_MANIPULATION_WARNING
     }
 
     override fun getItemCount() = categories?.size ?: 0
@@ -90,6 +93,12 @@ class Adapter: RecyclerView.Adapter<ViewHolder>() {
                             .inflate(R.layout.category_list_intro, parent, false)
             )
 
+        TYPE_MANIPULATION_WARNING ->
+            ManipulationWarningViewHolder(
+                    LayoutInflater.from(parent.context)
+                            .inflate(R.layout.manage_child_manipulation_warning, parent, false)
+            )
+
         else -> throw IllegalStateException()
     }
 
@@ -126,6 +135,9 @@ class Adapter: RecyclerView.Adapter<ViewHolder>() {
             CategoriesIntroductionHeader -> {
                 // nothing to do
             }
+            ManipulationWarningCategoryItem -> {
+                // nothing to do
+            }
         }.let {  }
     }
 }
@@ -133,6 +145,7 @@ class Adapter: RecyclerView.Adapter<ViewHolder>() {
 sealed class ViewHolder(view: View): RecyclerView.ViewHolder(view)
 class AddViewHolder(view: View): ViewHolder(view)
 class IntroViewHolder(view: View): ViewHolder(view)
+class ManipulationWarningViewHolder(view: View): ViewHolder(view)
 class ItemViewHolder(val binding: CategoryRichCardBinding): ViewHolder(binding.root)
 
 interface Handlers {
diff --git a/app/src/main/java/io/timelimit/android/ui/manage/child/category/Items.kt b/app/src/main/java/io/timelimit/android/ui/manage/child/category/Items.kt
index 6213caa..3167e56 100644
--- a/app/src/main/java/io/timelimit/android/ui/manage/child/category/Items.kt
+++ b/app/src/main/java/io/timelimit/android/ui/manage/child/category/Items.kt
@@ -20,6 +20,7 @@ import io.timelimit.android.data.model.Category
 sealed class ManageChildCategoriesListItem
 object CategoriesIntroductionHeader: ManageChildCategoriesListItem()
 object CreateCategoryItem: ManageChildCategoriesListItem()
+object ManipulationWarningCategoryItem: ManageChildCategoriesListItem()
 data class CategoryItem(
         val category: Category,
         val isBlockedTimeNow: Boolean,
diff --git a/app/src/main/java/io/timelimit/android/ui/manage/child/category/ManageChildCategoriesModel.kt b/app/src/main/java/io/timelimit/android/ui/manage/child/category/ManageChildCategoriesModel.kt
index c452de2..fc36f0c 100644
--- a/app/src/main/java/io/timelimit/android/ui/manage/child/category/ManageChildCategoriesModel.kt
+++ b/app/src/main/java/io/timelimit/android/ui/manage/child/category/ManageChildCategoriesModel.kt
@@ -40,6 +40,10 @@ class ManageChildCategoriesModel(application: Application): AndroidViewModel(app
         }
     }
 
+    private val childDevices = childId.switchMap { logic.database.device().getDevicesByUserId(it) }
+
+    private val hasChildDevicesWithManipulation = childDevices.map { devices -> devices.find { device -> device.hasAnyManipulation } != null }.ignoreUnchanged()
+
     private val childEntry = childId.switchMap { logic.database.user().getChildUserByIdLive(it) }
 
     private val childTimezone = childEntry.mapToTimezone()
@@ -113,7 +117,7 @@ class ManageChildCategoriesModel(application: Application): AndroidViewModel(app
 
     private val hasShownHint = logic.database.config().wereHintsShown(HintsToShow.CATEGORIES_INTRODUCTION)
 
-    val listContent = hasShownHint.switchMap { hasShownHint ->
+    private val listContentStep1 = hasShownHint.switchMap { hasShownHint ->
         categoryItems.map { categoryItems ->
             if (hasShownHint) {
                 categoryItems + listOf(CreateCategoryItem)
@@ -122,4 +126,14 @@ class ManageChildCategoriesModel(application: Application): AndroidViewModel(app
             }
         }
     }
+
+    val listContent = hasChildDevicesWithManipulation.switchMap { hasChildDevicesWithManipulation ->
+        listContentStep1.map { listContent ->
+            if (hasChildDevicesWithManipulation) {
+                listOf(ManipulationWarningCategoryItem) + listContent
+            } else {
+                listContent
+            }
+        }
+    }
 }
diff --git a/app/src/main/res/layout/manage_child_manipulation_warning.xml b/app/src/main/res/layout/manage_child_manipulation_warning.xml
new file mode 100644
index 0000000..a676f2b
--- /dev/null
+++ b/app/src/main/res/layout/manage_child_manipulation_warning.xml
@@ -0,0 +1,46 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Open TimeLimit Copyright <C> 2019 Jonas Lochmann
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation version 3 of the License.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program. If not, see <https://www.gnu.org/licenses/>.
+-->
+<androidx.cardview.widget.CardView
+    android:theme="@style/AppThemeDarkOverlay"
+    app:cardUseCompatPadding="true"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+    <LinearLayout
+        android:background="@color/orange"
+        android:orientation="vertical"
+        android:padding="8dp"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <TextView
+            android:drawablePadding="8dp"
+            android:drawableStart="@drawable/ic_warning_white_24dp"
+            android:text="@string/manage_child_manipulation_title"
+            android:textAppearance="?android:textAppearanceLarge"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content" />
+
+        <TextView
+            android:textAppearance="?android:textAppearanceMedium"
+            android:text="@string/manage_child_manipulation_text"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content" />
+
+    </LinearLayout>
+</androidx.cardview.widget.CardView>
diff --git a/app/src/main/res/values-de/strings-manage-child.xml b/app/src/main/res/values-de/strings-manage-child.xml
index da8eeb3..208686d 100644
--- a/app/src/main/res/values-de/strings-manage-child.xml
+++ b/app/src/main/res/values-de/strings-manage-child.xml
@@ -32,4 +32,9 @@
         Sie können mehrere Apps und Einschränkungen je Kategorie wählen.
         Das ermöglicht es z.B., eine Zeitbegrenzung für alle Spiele festzulegen.
     </string>
+
+    <string name="manage_child_manipulation_text">
+        Es gab eine Manipulation.
+        Gehen Sie zurück zur Übersicht und öffnen Sie den Geräte-Eintrag für Details.
+    </string>
 </resources>
diff --git a/app/src/main/res/values/strings-manage-child.xml b/app/src/main/res/values/strings-manage-child.xml
index 12cdec8..14b890b 100644
--- a/app/src/main/res/values/strings-manage-child.xml
+++ b/app/src/main/res/values/strings-manage-child.xml
@@ -32,4 +32,10 @@
         You can select multiple Apps and limits per category.
         This allows for example to set one limit for all games.
     </string>
+
+    <string name="manage_child_manipulation_title" translatable="false">@string/manage_device_manipulation_title</string>
+    <string name="manage_child_manipulation_text">
+        There was a manipulation.
+        Go back to the overview and open the device entry for details.
+    </string>
 </resources>