Move just denoted that it was a discussion topic, not a bug.
Touch and Ext have slightly different syntaxes for invoking the method of an Application method since Touch has a newer MVC package. (You can assume that future versions of Ext will be closer to Touch).
The following assumes we have adding a method named "myMethod" to our Application and we are using the default namespace of "MyApp". Change these to be appropriate to your application.
In controllers, you can access the application instance by invoking this.getApplication().
Touch stores a global reference to the application instance in MyApp.app.
In controllers, you can access the application instance by the property this.application.
Ext does not store a global reference to the application instance.
Once you have a reference to the application instance you can invoke the method.