Classy icons crafted according to Microsoft guidelines. Available in PNG and SVG. Free for a link
Feather Icons - Simply beautiful open source icons
Noisli - Noisli is a fantastic background noise and color generator for working and relaxing. Online soothing ambient sounds like White noise, Rain and Coffee Shop.
IconStore - Free icon packs by first-class designers
Focus Noise - Productivity sounds and color noises to stay focused at work
Flat Icons - 20,000 unique, customizable icons with free lifetime updates
Defonic - Create a unique sound environment at home or in the office