Bug fixes and improvements

Fixed subscription bugs

Fixed premium upgrade bugs

Language Progress Indicators are added.
Study Mode is added.
Quiz Mode is added.
Bookmarking is available.
Ability to play the sound for text for different languages is available.
Added thousands of words and sentences of different difficultly level.
Added All Bookmarks Tab in the Menu items.
Bug Fix for Text To Speech issue.
Fixed app name in About Us screen.
Changed hamburger menu icon.
Removed menu icon from all screens except Home.