with BookBuddi Talking Picture Books you can increase your learning speed without working harder by listening to your textbook in repeat mode, thereby increasing your retention rate and reducing fatigue (you don't have to read, just listen).
A level Maths has Talking Equations for quick revision or self-tuition.
The computer is doing all of your reading work, with speedread and repetition control it's like having a brain machine. Please see the demo video above.
Many books are free such as A level Maths C1.
A Level Maths C2 and C3 are £1.99 for both.
I use the £50 Amazon Fire 7.
BookBuddi is not for the click happy because almost everything is on 1 page and it's fast, as the internet is not required after downloading.