Reuse of capture app form builder logic

Hi, there i am trying the use the form builder logic from capture-app( GitHub - dhis2/capture-app: Next version DHIS 2 data capture app) but as i am new in to the dhis not able to understand the code. i am trying to build new app like tracker-capture-app (registration form, stages froms etc.), please help me on this how i can use that form builder in my app.