Sometimes there is a delay between when a user interacts with a widget and when something actually "happens".  This is especially evident on mobile apps (e.g. AppBuilder) when there are complex bound value changes/dom changes.

An example would be clicking a button in a ButtonGroup to display a ListView that uses a remote bound DataSource which displays images and text in the list.  Sometimes, in scenarios such as this, you'll click on the button of the ButtonGroup and nothing will happen for a few seconds.  This makes for a poor user experience.

Since we can't make the app react instantaneously we really need to at least make it appear that it is or else the app feels "slow".  Though some Kendo Mobile widgets attempt to aid with this by using the application.showLoading() when engaging in a "long" process, even that will ofen have a delay before showing.  I'm not sure why that is, maybe it's due to the order in which it is processed.

In any case, the first thing that every widget should do before anything else is indicate to the user that "yes, I acknowledge that you just clicked/tapped me and I am working".  An example of this is in iOS native apps when you are trying to delete an application.  As soon as you click the "x" to uninstall the app, it turns gray, even though it may take a few seconds before the app actually uninstalls.  If all Kendo Mobile UI Widgets gave feedback instantaneously, that would go a long way to covering up some performance issues that might exist with the framework.