Hi,
you can find the effective iOS library in PDFLib folder, where you can find PDFObjc class, PDFIOS.h header and libRDPDFLib.a (that is the effective core library).
To open a pdf file you can take a look at RDPDFViewController, and focus on PDFOpen method, that initializes the m_doc var (PDFDoc instance, that contains the pdf data) and the m_view var (PDFView instance), that is the effective view that shows the pdf file.
m_doc and m_view variables should be enough to simply show a pdf file.
RDPDFViewController implements also PDFViewDelegate methods, used to manage some actions of PDFView instance like single tap and annotation management.
To show a pdf file without Radaee watermark you need a valid license, that you can activate with APP_Init method of PDFVGlobal class.
The demo project call APP_Init method in RDAppDelegate class and uses a demo premium license.