Add features to an already created e reader

Currently we have an e-Reader that accepts .txt, .pdf, and .epub files. Please add these other features:
Natural TTS for multiple languages.
text to speech with concurrent word highlighting.
right click on a word or right click on a highlighted phrase to reveal a list of options:
"define" - which should define the meaning of the word/phrase highlighted
"examples" - provides similar other examples of the highlighted being used

also please create a system that saves all words that the user asks to define into a repository of 'unknown words'

create a digital library that displays all books and documents from the directory