A few weeks ago, I came up with the idea for learning a new language by reading a familiar book with words replaced/translated, sparsely at first, then, by the end of the book (hence the name of the website: http://bytheendofthisbook.com ), the text will all be in the new language. I started an example on the site using the first chapter of Harry Potter and the Deathly Hallows.
When reading the book, you will be presented with a new word, highlighted and bold, and usually something that you can figure out within the context of the sentence, with the ability to click on it to see the original text. The next time the word is used, it will again be highlighted and bold. From that point on, the word will be bold. So, by the time you get to the end of the book, the text will be totally bold.
Here is an example:
Once I started putting this together, I realized I would need money to hire someone to translate books and then, most importantly, licensing.
So I started a Kickstarter campaign to see if people saw the potential that I see in this. Here is the link:
https://www.kickstarter.com/projects/535190562/by-the-end-of-this-book
Check it out and see if you like!