The message “Under development” means that we are still working on this feature. It will be added in a future update.
Please check if there are any updates for Hue Essentials on the store you downloaded it from.
If you are using the desktop version of Hue Essentials, you may be able to use Hue Essentials on your phone for this feature.
Let us know if there is any specific feature that is still under development which you would like to see added.