Richard, some of the functions you mentioned are readily available in the Drone Harmony app:
1. You can
format the SD card by going to the menu -> Drone -> Format SD card
2. The
RTH option is available as one of the end-of-flight options when you are flying plans with the app. The button on the RC also works, but in case you decide to take manual control of the drone, we recommend that you change modes to "sport" (causes the drone to hoover in place) and start giving manual command like RTH then.
3. Many more options that you might be using DJI GO for at the moment will be added with the following updates to the app, notably the
control of camera parameters.
You will likely need to keep using the DJI GO app at least for firmware updates in the near future.
A lot more information is available in our
FAQ. Feel free to have a look and of course just ask us directly.
Best,
DH Team