Helpful (mostly free) design resources for software developers

I am a primarily a coder, and although I can implement design, websites and am creative from a technical perspective and have a eye for design, I don't really have the skills to originate graphic design, multimedia or user interface elements quickly whilst getting the development work done.

To help make things look good and professional, I have compiled a collection of useful design resources for developers who need some extra help with the design side of things.

Photographic images https://unsplash.com
 https://unsplash.com - Free images (and they are pretty good)

 User interface (UI) / User Experience (UX) and for OG's: Graphics User Interface (GUIs)

https://getbootstrap.com - UI design / CSS Framework

https://www.font-awsome.com - Web Icons

 Graphic elements / images

https://trianglify.io - Low-poly style background
 (or a free coded version here: http://jsfiddle.net/brightertools/69Ljdusc/10)

https://undraw.co/illustrations - Free illustrations (with colour selection/modification) http://www.xiconeditor.com/
 http://www.xiconeditor.com/ - Create website icons (favicon.ico)

Graphics Applications

https://www.getpaint.net/index.html - Image Manipulation application
 (although I use also Adobe CC, this tools is great for quick for image resizing and editing)
 

Content Management Systems / Documentation Tools
 https://wix.com - Create content/marketing websites
 (sometimes a basic website without coding and minimal setup is required, in these instances I have used Wix with great effect, really? Wix? yes, please read this blog post.

https://www.gitbook.com - Create good looking documentation

Tools

http://www.iconico.com/colorpic - Pixel colour picker across desktop / any app image
 

..and some coding utilities..

https://guidgenerator.com/ - Generate some GUIDs

 I use these professionally and am personally recommending them.