I've confirmed the
P4P+ Android device will not have access to the Android PlayStore.
This may help...
I have the Yuneec Typhoon H and although the controller is an Android based 7" tablet, which you can load Apps on "manually", you can't load apps via the Google Play Store. I've tried many times to get the Google Play Store working, which is possible, but you can't download Apps from it or have it update Apps on the tablet. Yuneec has done something to ensure this does not happen, so that they control the updates. When you turn on the controller for the Typhoon H, it goes immediately into the FLIGHTMODE software (which is like the DJI GO App). You can then choose to go into Android if you wish and start up other Apps (Photo Gallery, Calendar, Facebook, Twitter, etc) or play with all the Android settings. It is pretty much an Android Tablet that you'd buy from any store, except the Google Play Store will not work in its entirety. Many Apps on my tablet I have placed there manually.
I would guess that DJI has done the same thing with the
P4P+ controller and the CrystalSky controller. This means that when you power them on they immediately load the DJI GO App. DJI will have an option to go into Android. From there you can launch other Apps and play with all the Android settings (i.e., set up your WiFi, date, time, background, google account settings, etc). Because of this, you could then do the same that is done on the Typhoon H controller... You can place any Android App on a mico SD. Android Apps all have the file extension APK. Just download the Litchi APK file (do a search for Litchi.APK) off the internet and place it on a micro SD card. Place that card into the controller, go into Android and manually load the App.
NOTE: I do not yet have the
P4P+ controller to try this, and I'm just providing my thoughts based on my experience with the Yuneec Typhoon H controller.