UI Widgets & Components Tools

Desktop & Mobile:

• Bootstrap
• Kendo UI [free to $]
• Material ui
• Materialize
• Metro UI
• Office UI Fabric
• Polymer Paper Elements
• Semantic UI
• Webix [$]

Desktop (NW.js and Electron):

• Photon
• React UI Components for OS X El Capitan and Windows 10

Mobile Focused:

• Framework7
• Kendo UI Mobile
• Mobile Angular UI
• Ratchet