Radix Icons - A crisp set of 15×15 icons. Open source.
Topstyle - TopStyle contains powerful tools for building standards-compliant web sites.
Bjango App Icon Templates - App icon templates for PS, Ai, Sketch and Affinity Designer
Stylizer - A productivity-focused real-time CSS editor for serious web developers. Mac OS X and Windows.
MakeAppIcon - MakeAppIcon resizes and optimizes your icon designs into all formats needed for iOS and Android mobile app!
EnjoyCSS - CSS generator for rich graphical styles without coding