Sorry, about the delay in replying but I’ll do my best to walk you through it.
First, the overall concept. The idea is that you install the virtual control as a new device. This is the device you will use as the “Master” device to control your physical bulbs “slaves” using the application.
How to install the device
In the IDE go into the “My Device Handlers” and click on the “Create new Device Handler”. Then click on the “From Code” tab and paste the code for the device handler into there and click “Create” Once you have done that, click “Save” and then “Publish” and “For Me”. This will add this new virtual ZigBee RGBW Bulb to your available devices. Which we will use in a bit.
How to install the SmartApp
Click on “SmartApps” in the IDE. From there click on “New SmartApp” and then the “From Code” tab. Paste the code for the SmartApp into the form and click on “Create”. Finally click on “Save” then “Publish” and “For Me”. This will add the “ZigBee RGBW Bulb Grouper” SmartApp to your list of available apps on your mobile. We’ll set this up in just a few steps.
How to setup the virtual device
Now we need to setup the virtual device. From the IDE click on “Devices” and “New Device”. You can name this whatever you want and give it whatever label you want "I used “Living room lights (virtual)” for both. Just so I knew what it was. Leave “Zigbee Id” empty and put something unique into “Device Network Id” (I used living-room-lights-virtual). Pick the “ZigBee Virtual RGBW Bulb” in the “Type” list (should be towards the very bottom) and select the Location and Hub you want to install this device on.
Installing and configuring the SmartApp
Now that the hard part is done it’s time to set it all up. On your mobile device go to “Marketplace”. Go into SmartApps and select “My Apps” (at the very bottom). From there you can open up and configure the “ZigBee RGBW Bulb Grouper” application. Pick the virtual bulb device you created before as the “Master device” and the bulbs you want to control as the “Slave devices”. Give it a name (optional, but a good idea) and click “Done”.
Now that you’ve done all of that you should be able find the virtual device in your “Things” (I edited the device on my mobile and put it into a group/room) and use it to control your bulbs.
Hope this helps, and if not just let me know and I’ll do my best to help some more!