You may also want to download WebView Developer Browser from the Google Play store so that you can quickly run the web version of webmaker-app. This is the browser Cordova uses on Android 4.2.
If you don't have an Android device, you can test on an Android emulator for 4.2. First, run the following to check what targets are available:
android list targets
You will want to use android-17. Choose a name for your profile and run the following to create an avd:
android create avd -n myemulator -t android-17
Go ahead and use hardware defaults when it prompts you. Now, you can use your emulator when building and running webmaker app with the following commands:
cordova prepare
cordova run android --target myemulator