It is not possible to download the .apk file of your app for test purposes.
You can test your app by downloading the AppMachine Previewer app from the playstore using this link http://apps.appmachine.com/previewer.
Or view the app in the live ios viewer.
The code we use to build your app is the same code we use for the app previewer. So your app will look the same as the one shown in the app previewer, just without the login of the previewer.