504 absolutely essential words is a book containing words which are familiar in daily conversations, news broadcasting, movies, etc... also, you can have a whole new educational experience due to the updated features of this app.

Key features :
- Reading ability, which can be activated by touching the desired part of the text & deactivated by retouching any part of the display.
- The reading speed of this app is adjustable as the skills and the desire of the user.
- by selecting the needed options, the user will be able to read the book without any problem, the screen will stay waked up as long as it is necessary.