Join Stuart Ashworth, Sencha MVP, in the fourth part of the series building an Email Client using just the Sencha Ext JS framework and components.
Part 4 starts to add in the Modern framework, showing how to start the process of refactoring and reusing existing business logic and data stores to support both Classic and Modern touch enable browsers.
Why not code along with a copy of Sencha from https://www.sencha.com/