diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a2b8f73..749a3a8 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -29,12 +29,14 @@ Missing/outdated strings:
     * `optionsMirroringCategoryDescription`
     * `optionsMirroringEnabled`
     * `optionsMirroringAppId`
+    * `popupMediaTypeAppNotFound`
 
 * `es`
     * `optionsMirroringCategoryName`
     * `optionsMirroringCategoryDescription`
     * `optionsMirroringEnabled`
     * `optionsMirroringAppId`
+    & `popupMediaTypeAppNotFound`
 
 * `nl`
     * `optionsBridgeBackupEnabled`
@@ -45,6 +47,7 @@ Missing/outdated strings:
     * `optionsMirroringCategoryDescription`
     * `optionsMirroringEnabled`
     * `optionsMirroringAppId`
+    * `popupMediaTypeAppNotFound`
 
 
 ### NSIS Installer Localization
diff --git a/ext/src/_locales/en/messages.json b/ext/src/_locales/en/messages.json
index 3cccfc8..e1f8410 100755
--- a/ext/src/_locales/en/messages.json
+++ b/ext/src/_locales/en/messages.json
@@ -13,6 +13,10 @@
         "message": "this site's app"
       , "description": "Receiver selector media type <option> text for current site's sender application."
     }
+  , "popupMediaTypeAppNotFound": {
+        "message": "this site's app (not found)"
+      , "description": "Receiver selector media type <option> text for current site's sender application if none found."
+    }
   , "popupMediaTypeAppMedia": {
         "message": "this media"
       , "description": "Receiver selector media type <option> text for media casting."
diff --git a/ext/src/ui/popup/index.tsx b/ext/src/ui/popup/index.tsx
index 062b684..33fdd0a 100755
--- a/ext/src/ui/popup/index.tsx
+++ b/ext/src/ui/popup/index.tsx
@@ -149,6 +149,8 @@ class PopupApp extends Component<{}, PopupAppState> {
 
         const isSelectedMediaTypeAvailable =
                 !!(this.state.availableMediaTypes & this.state.mediaType)
+        const isAppMediaTypeAvailable = !!(this.state.availableMediaTypes
+                & ReceiverSelectorMediaType.App);
 
         return (
             <div>
@@ -163,10 +165,11 @@ class PopupApp extends Component<{}, PopupAppState> {
 
                             <option value={ ReceiverSelectorMediaType.App }
                                     selected={ isAppMediaTypeSelected }
-                                    disabled={ !(this.state.availableMediaTypes
-                                            & ReceiverSelectorMediaType.App) }>
+                                    disabled={ !isAppMediaTypeAvailable }>
                                 { (this.state.requestedAppId && knownApps[this.state.requestedAppId]?.name)
-                                            ?? _("popupMediaTypeApp") }
+                                            ?? isAppMediaTypeAvailable
+                                                ? _("popupMediaTypeApp")
+                                                : _("popupMediaTypeAppNotFound") }
                             </option>
 
                             { this.state.mirroringEnabled &&