Hello Vani,

The aforementioned app is a very useful app in increasing the strength of the vocabulary, but when it comes to CLAT, there are certain basic norms that are followed for the vocabulary section, it is advisable to stick to the books and even apps that are designed especially for CLAT vocabulary. Every exam has different set of questions and the basic nature of these questions asked in the exams are usually followed year by year. While the app you mentioned may strengthen your vocabulary it may not provide you a insight into the CLAT exams' vocab. This all your effort will be less goal oriented and more self development oriented which is a useful thing but not much when it comes to crack an examination.

Here is the list of best book for English section:

• Word Power Made Easy by Norman Lewis.
• High School English Grammar and Composition by Wren & Martin.
• English is Easy by Chetananand Singh.
• Objective General English by RS Aggarwal.
• Barron's Pocket Guide to Vocabulary

I hope the answer was helpful. All the best.