You might see native installs on the Android Analytics panel even if you never uploaded your app to the Android market and never created an Android developer account.
This might happen because your app was probably tested on native devices, where the APK file of your App has been installed.
You can install the native app by using the corresponding APK file from your Appsbuilder dashboard.
Click on the Promote tab at the top:
Then click on Publish on Stores from the left hand sidebar:
Click on the Google Play tab:
Then open the Download your apk file box:
and click on download native app.
Each install, even though the app is not uploaded to Google Play, will be counted as a native user on the Mobile platform.