Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
Octicons - Your project. GitHub's icons.
GIMP - GIMP is a multiplatform photo manipulation tool.
Themify Icons - A complete set of icons for use in web design and apps, consisting of 320+ pixel-perfect, hand-crafted icons that draw inspiration from Apple iOS 7.
Affinity Photo - Affinity is the imaging and design suite for creative professionals exclusively for Mac.
WebHostingHub Glyphs - High quality icons that are easy to use with Bootstrap, other CSS frameworks and in any web projects.