After several failed attempts of trying to install APKs on the DJI Smart Controller I've successfully installed Google Play Store on the DJI Smart Controller. Using these steps you can download third party apps from the Play Store on the Smart Controller without rooting. For a list of apps that are currently working with the SC scroll to the bottom of this page.

The secret is to use the same method people with devices that are blocked from using Google services do, for example, the Chinese phone by Xiaomi. After installing the Google Installer 2.0 APK, the most important thing to do is identify your Google Service Framework Device-ID and register it. As you can see this is still a work in progress - if you have any suggestions or changes please let me know.

Warning: These are the steps I used to get Google Play Store working on my DJI Smart Controller. If you attempt this you do it at your own risk. I am not guaranteeing that it will work for you and you are the only one liable for any damages this may causes to your own equipment. I am not associated with DJI nor has this been tested.