Update App Preview docs (#3111)

Author: helinanever

content/flutter-testing/app-preview.md

@@ -1,13 +1,13 @@
 ---
 title: Previewing apps in the browser
-description: How to preview and test your iOS or Android app on a simulator or emulator running in the browser
+description: Test your iOS or Android app in the browser with Stellar App Preview
 weight: 4
 aliases:
 ---
 
-Codemagic allows you to launch your iOS or Android app on an iOS simulator or Android emulator running in the browser, regardless of the operating system you are using. Test your app against different device and OS configurations, emulate GPS location or demo the latest app version without needing access to a physical device. 
+Stellar is our iOS simulator and Android emulator running in your browser. Launch and interact with your iOS or Android app right in the browser, regardless of the operating system you are using. Test your app against different device and OS configurations, emulate GPS location or demo the latest app version without needing access to a physical device. 
 
-**Tip:** The following sections describe creating previewable artifacts using codemagic.yaml. If you're using the Flutter Workflow Editor, follow the instructions [here](../flutter-testing/app-preview).
+**Tip:** The following sections describe creating previewable artifacts using Flutter Workflow Editor. If you're using codemagic.yaml, follow the instructions [here](../yaml-testing/app-preview).
 
 ## Enabling App Preview
 

content/yaml-testing/app-preview.md

@@ -1,11 +1,11 @@
 ---
 title: Previewing apps in the browser
-description: How to preview and test your iOS or Android app in the browser
+description: Test your iOS or Android app in the browser with Stellar App Preview
 weight: 4
 aliases:
 ---
 
-Codemagic allows you to launch your iOS or Android app on an iOS simulator or Android emulator running in the browser, regardless of the operating system you are using. Test your app against different device and OS configurations, emulate GPS location or demo the latest app version without needing access to a physical device. 
+Stellar is our iOS simulator and Android emulator running in your browser. Launch and interact with your iOS or Android app right in the browser, regardless of the operating system you are using. Test your app against different device and OS configurations, emulate GPS location or demo the latest app version without needing access to a physical device. 
 
 **Tip:** The following sections describe creating previewable artifacts using codemagic.yaml. If you're using the Flutter Workflow Editor, follow the instructions [here](../flutter-testing/app-preview).