Sencha Themer is a visual tool for creating themes for Ext JS apps without code. It allows live updates to themes and supports common components. Sencha held a theming contest with a $2500 top prize, and the document highlights the winning themes designed by Dean Ranft, Nils Dehl, and Mike Giddens. The next release of Themer will add support for theming Ext JS 6.5 and Ext React apps.