Everyone knows that "Vocabulary in Use" is an excellent set of books for English learners. However, the biggest drawback of the paper or e-book versions is that it's very hard and not convenient to look up a word in them. Therefore, I decided to convert into Babylon version.
This is the most convenient way to use "Vocabulary In Use" book. You can easily find a page in "Vocabulary in use" book just by typing a word contained in the page. For example, by looking up the word "cat" or "dog" you will reach the page titled "Animals" which provides you with many other kinds of animals and words related to them. It is particularly useful when we practise speaking and writing.
The three levels are 'Advanced', 'Intermediate', and 'Elementary'.