diff --git a/app/src/main/java/fr/free/nrw/commons/customselector/ui/adapter/ImageAdapter.kt b/app/src/main/java/fr/free/nrw/commons/customselector/ui/adapter/ImageAdapter.kt
index 671276203..ea7505aeb 100644
--- a/app/src/main/java/fr/free/nrw/commons/customselector/ui/adapter/ImageAdapter.kt
+++ b/app/src/main/java/fr/free/nrw/commons/customselector/ui/adapter/ImageAdapter.kt
@@ -110,7 +110,7 @@ class ImageAdapter(
             }
         } else {
             if(holder.isItemUploaded()){
-                Toast.makeText(context, "Already Uploaded image", Toast.LENGTH_SHORT).show()
+                Toast.makeText(context, R.string.custom_selector_already_uploaded_image_text, Toast.LENGTH_SHORT).show()
             } else {
                 selectedImages.add(images[position])
                 notifyItemChanged(position, ImageSelectedOrUpdated())
diff --git a/app/src/main/java/fr/free/nrw/commons/customselector/ui/selector/CustomSelectorActivity.kt b/app/src/main/java/fr/free/nrw/commons/customselector/ui/selector/CustomSelectorActivity.kt
index 219239974..02b0a8b1a 100644
--- a/app/src/main/java/fr/free/nrw/commons/customselector/ui/selector/CustomSelectorActivity.kt
+++ b/app/src/main/java/fr/free/nrw/commons/customselector/ui/selector/CustomSelectorActivity.kt
@@ -1,10 +1,13 @@
 package fr.free.nrw.commons.customselector.ui.selector
 
 import android.app.Activity
+import android.app.Dialog
 import android.content.Intent
 import android.content.SharedPreferences
 import android.os.Bundle
 import android.view.View
+import android.view.Window
+import android.widget.Button
 import android.widget.ImageButton
 import android.widget.TextView
 import androidx.lifecycle.ViewModelProvider
@@ -16,6 +19,7 @@ import fr.free.nrw.commons.theme.BaseActivity
 import java.io.File
 import javax.inject.Inject
 
+
 /**
  * Custom Selector Activity.
  */
@@ -55,10 +59,18 @@ class CustomSelectorActivity: BaseActivity(), FolderClickListener, ImageSelectLi
         setContentView(R.layout.activity_custom_selector)
 
         prefs =  applicationContext.getSharedPreferences("CustomSelector", MODE_PRIVATE)
-        viewModel = ViewModelProvider(this, customSelectorViewModelFactory).get(CustomSelectorViewModel::class.java)
+        viewModel = ViewModelProvider(this, customSelectorViewModelFactory).get(
+            CustomSelectorViewModel::class.java
+        )
 
         setupViews()
 
+        if(prefs.getBoolean("customSelectorFirstLaunch", true)) {
+            // show welcome dialog on first launch
+            showWelcomeDialog()
+            prefs.edit().putBoolean("customSelectorFirstLaunch", false).apply()
+        }
+
         // Open folder if saved in prefs.
         if(prefs.contains(FOLDER_ID)){
             val lastOpenFolderId: Long = prefs.getLong(FOLDER_ID, 0L)
@@ -68,6 +80,17 @@ class CustomSelectorActivity: BaseActivity(), FolderClickListener, ImageSelectLi
         }
     }
 
+    /**
+     * Show Custom Selector Welcome Dialog.
+     */
+    private fun showWelcomeDialog() {
+        val dialog = Dialog(this)
+        dialog.requestWindowFeature(Window.FEATURE_NO_TITLE)
+        dialog.setContentView(R.layout.custom_selector_info_dialog)
+        (dialog.findViewById(R.id.btn_ok) as Button).setOnClickListener { dialog.dismiss() }
+        dialog.show()
+    }
+
     /**
      * Set up view, default folder view.
      */
diff --git a/app/src/main/res/layout/custom_selector_info_dialog.xml b/app/src/main/res/layout/custom_selector_info_dialog.xml
new file mode 100644
index 000000000..a34f247dd
--- /dev/null
+++ b/app/src/main/res/layout/custom_selector_info_dialog.xml
@@ -0,0 +1,133 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout
+  xmlns:android="http://schemas.android.com/apk/res/android"
+  xmlns:app="http://schemas.android.com/apk/res-auto"
+  xmlns:tools="http://schemas.android.com/tools"
+  android:layout_height="wrap_content"
+  android:layout_width="match_parent"
+  android:layout_margin="@dimen/dimen_10">
+  <ScrollView
+    android:layout_height="match_parent"
+    android:layout_width="match_parent">
+
+    <LinearLayout
+      android:layout_width="match_parent"
+      android:layout_height="wrap_content"
+      android:orientation="vertical" >
+
+      <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center"
+        android:text="@string/welcome_custom_picture_selector_text"
+        android:textSize="@dimen/normal_text"
+        android:textStyle="bold"/>
+
+      <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center"
+        android:layout_margin="@dimen/dimen_10"
+        android:text="@string/custom_selector_info_text1"
+        android:textSize="@dimen/description_text_size"
+        android:textStyle="bold"/>
+
+      <LinearLayout
+        android:layout_marginHorizontal="@dimen/dimen_10"
+        android:layout_width="match_parent"
+        android:layout_height="@dimen/dimen_150"
+        android:layout_gravity="center"
+        android:orientation="horizontal"
+        >
+
+        <androidx.constraintlayout.widget.ConstraintLayout
+          android:layout_weight="1"
+          android:layout_width="0dp"
+          android:padding="@dimen/dimen_2"
+          android:layout_height="match_parent">
+
+          <androidx.cardview.widget.CardView
+            android:layout_width="match_parent"
+            app:cardCornerRadius="@dimen/dimen_6"
+            android:layout_height="match_parent"
+            app:cardElevation="@dimen/dimen_2"
+            android:id="@+id/view"
+            app:layout_constraintTop_toTopOf="parent">
+
+              <androidx.appcompat.widget.AppCompatImageView
+                android:id="@+id/image_thumbnail"
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:scaleType="centerCrop"
+                android:src="@drawable/welcome_image_example"/>
+
+          </androidx.cardview.widget.CardView>
+        </androidx.constraintlayout.widget.ConstraintLayout>
+
+        <androidx.constraintlayout.widget.ConstraintLayout
+          android:layout_weight="1"
+          android:layout_width="0dp"
+          android:padding="@dimen/dimen_2"
+          android:layout_height="match_parent">
+
+          <androidx.cardview.widget.CardView
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            app:cardCornerRadius="@dimen/dimen_6"
+            app:cardElevation="@dimen/dimen_2"
+            android:id="@+id/view_uploaded"
+            app:layout_constraintTop_toTopOf="parent">
+
+            <androidx.constraintlayout.widget.ConstraintLayout
+              android:layout_width="match_parent"
+              android:layout_height="match_parent">
+
+              <androidx.appcompat.widget.AppCompatImageView
+                android:id="@+id/image_thumbnail_uploaded"
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:scaleType="centerCrop"
+                android:src="@drawable/welcome_image_example"/>
+
+              <View
+                android:id="@+id/uploaded_overlay"
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:alpha="0.15"
+                android:background="@color/black"
+                tools:layout_editor_absoluteX="0dp"
+                tools:layout_editor_absoluteY="203dp" />
+
+              <ImageView
+                android:id="@+id/uploaded_overlay_icon"
+                android:layout_width="@dimen/dimen_72"
+                android:layout_height="@dimen/dimen_72"
+                app:layout_constraintEnd_toEndOf="parent"
+                app:layout_constraintBottom_toBottomOf="parent"
+                app:srcCompat="@drawable/commons"
+                />
+            </androidx.constraintlayout.widget.ConstraintLayout>
+          </androidx.cardview.widget.CardView>
+        </androidx.constraintlayout.widget.ConstraintLayout>
+      </LinearLayout>
+
+      <TextView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_margin="@dimen/dimen_10"
+        android:gravity="center"
+        android:text="@string/custom_selector_info_text2"
+        android:textSize="@dimen/description_text_size"
+        android:textStyle="bold"/>
+
+      <androidx.appcompat.widget.AppCompatButton
+        android:id="@+id/btn_ok"
+        android:layout_marginHorizontal="@dimen/dimen_40"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:textColor="@color/white"
+        android:text="@string/welcome_custom_selector_ok"
+        />
+    </LinearLayout>
+  </ScrollView>
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index e43bae7b5..4a04fe47d 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -651,5 +651,10 @@ Upload your first media by tapping on the add button.</string>
   <string name="custom_selector_empty_text">No Images</string>
   <string name="done">Done</string>
   <string name="back">Back</string>
+  <string name="welcome_custom_picture_selector_text">Welcome to Custom Picture Selector</string>
+  <string name="custom_selector_info_text1">This picker shows differently pictures that are already to Commons.</string>
+  <string name="custom_selector_info_text2">Unlike the picture on the left, the picture on the right has the Commons logo indicating it is already uploaded.</string>
+  <string name="welcome_custom_selector_ok">Awesome</string>
+  <string name="custom_selector_already_uploaded_image_text">This image has already been uploaded to Commons.</string>
 
 </resources>