Whenever you appify a list K2 Appit for SharePoint will automagically create a couple of forms. If you want to edit these OOB forms by adding/removing views it is best to do this before you build your workflow (assuming you're building one.)  The reason for this is that when you elect to build a workflow off of an Appified list, K2 will create a host of item references between views, controls and other objects on the form and connect them to the workflow. If you create the workflow before removing these items you run the risk of breaking reference and Appit doesn't like that and will throw an error to this effect:

When the workflow start rule gets triggered, a missing item reference will get thrown as the workflow expects something that isn't there. The best way to avoid this is to hold off on building out a workflow until the form is situated.