As forms are built in the Form Manager, preview mode can be used to view and alter the layout. Data entry and validation can be accomplished easily by tapping the Subjects icon in the navigation bar. When finished, tap on the menu, which will have saved where you left off in the form builder.
When testing a study, its also important to play different user roles so you can see what the different types of users on a study would see (i.e. Coordinators, Monitors, and Data Managers - to name a few).
TrialKit gives you the ability to very easily change your role. To do this, a special permission needs to be enabled for the role you actually serve on the study. Read here on how to enable the permission to dynamically change your role.