Recently I purchase a 5.5 crystal sky and installed several much needed apps. It comes with DJI Go installed so I just had to add Litchi. EVO Explorer and weather apps. Now Litchi has to be purchased from Amazon even if you already have a android version you paid for the Amazon app is the only one that will work. Next the Explorer which is free and installed fine however the maps don't work. The work around is to install google play services which does not work on the CS and tosses an occasional error that it stopped working however it does not crash the unit or interfere and the google maps now work great. All these app are installed by first downloading the APK files to a usb stick or card then run the install with the CS, I use the CS with the DJI drones and EVO and it's perfect in bright sun and the apps work flawlessly. I also modified the EVO controller so I can insert the CS in the handles like the DJI controllers. The CS is installed on a 3D printed adapter which I got off Thingyverse.