Version 4.3.8 is the iOS (Apple Version) and since three days this is available in the Apple Store... I just checked it.
The latest Android Version I do not know about.
Hi Darren. No, you don't have to. You can directly go to App Store if you are using an Apple device. Then look for DJI Go 4 App and hit update. If you have further question, please let me know. Thank you.