UI/widget tools

# UI widget tools ##### Desktop & Mobile: - [Kendo UI](http://www.telerik.com/kendo-ui) [free to $] - [Webix](http://webix.com/) [$] - [Semantic UI](http://semantic-ui.com/) - [Metro UI](http://metroui.org.ua/) - [Bootstrap](http://getbootstrap.com/components/) - [Materialize](http://materializecss.com/) - [Material ui](http://material-ui.com/) - [Polymer Paper Elements](https://elements.polymer-project.org/browse?package=paper-elements) - [photonkit](http://photonkit.com/) ##### Mobile focused: - [Ratchet](http://goratchet.com/) - [Kendo UI Mobile](http://demos.telerik.com/kendo-ui/m/index) - [Mobile Angular UI](http://mobileangularui.com/) - [Framework7](http://www.idangero.us/framework7)