Can be used to create super colorful 3D like warps in Affinity Photo space, sheets, etc
Open a new document and then go to the layer menu and new layer and then goto the gradient tool and add a basic gradient, you can also go to the swatches panel via the view menu and studio and then add a preset to the current fill, the more colorful the better.
Go to the panel via view menu and select the red. Set the navigator to a very large size as you can see the activity across the red, green and blue and not just the gray scale you see when you select the red or green etc.
Select the tool in the tools panel, if it is not there then go to the view menu and customize your tools to restore it. When you use the tool, you will see a bounding box around the layer though you are not modifying the layer at this point, just the channels so you can distort the red in all kinds of ways by dragging this bounding box, creating folds in your channel space. You can also double click the design and add some additional node points to add even more amazing distortion. Once you have finished with that, click apply in the top left.
Go to the green and then select the tool again and distort the green pixels and so on. You can then do exactly the same thing as before and distort the design in all kinds of ways but you are working with the green and not the red.
Select the blue composite and then work with that in a similar way
You can restore to RGB (or CMYK etc) by clicking the circular button at the top of the panel. Once you have that, you should have a really beautiful design.
You can also use the tool with that now and that will distort the actual layer.