[Adding icons]

To do that, you have to create an asset out of each icon and add those to the same set. (So, open the SVG in Affinity Designer, select every component, create a new asset category and then, from the hamburger menu, chose "Create asset from selection").
This can then be [optionally] exported as a .afassets file to transfer the asset library to other computers or share it.

[Gradient Pack - uiGradient.com]

As a web designer, I find websites like uiGradients.com a quite useful resource, with a massive selection of ready-made gradients (and css code for those).

This palette is a complete (01.09.2018) pack of all gradients alongside their names, hand-imported over the course of an afternoon and a few podcasts.

I don't think you can copyright colors/gradients, but the GitHub repository of the uiGradients.com website is licensed under MIT. I'll try to keep the file up to date with the website, but if there's a missing gradient or a error, please tell me about it.

Enjoy: uiGradients.com.zip

 

(A preview will follow soon)