The following diagram explains the relationship among Creative Book Builder Family's apps:
Creative Widget Builder generates widgets based on iBooks Widget format. Those widgets can be applied to iBooks Author, Creative Book Builder and TouchAppCreator as well.
Creative Book Builder is a powerful and professional tool to generate EPUB that can be read through any EPUB readers. Also, CBB can export book into HTML5 books that can be read through any web browsers. HTML5 books can include some widgets that cannot be used in EPUB, e.g. iframe, and embed html code.
Creative Book Reader is an free app to read HTML5 books. It helps you distribute your HTML5 books easily.
TouchAppCreator allows everyone to create mobile optimized and content centric web app. The published web app can be added to Home Screen. It can import EPUB generated by CBB. On the other hand, CBB can import apps created by TouchAppCreator.
TouchAppViewer is also an free app to browse web app offline. It helps you distribute your web app easily.