The topics and subject you will find in the app are given below
Attributes
Data types
Delivery
Development
Document type declaration
Element examples
Frameset versus transitional
Headings
History html
HTML 2
HTML 3
HTML 4
HTML 5
HTML Application
HTML draft version timeline
HTML e-mail
HTML versions timeline
HTTP
Markup
Naming conventions
Semantic HTML
SGML-based versus XML-based HTML
Summary of specification versions
WHATWG HTML versus HTML5
WYSIWYG editors