What would be the best apps and other means for preparing for CAT examination and improving English? Also if anyone can help me guide through the institutes which would be better for preparing for the CAT program.
Writing can also improve your language and grammar. For this I suggest you to start writing on some topic of about 500+ words on a notepad or notebook. Then type the same word in ms word. Now download, install ginger software on your system, check the grammar mistake.
Ginger software is very helpful to check grammar.
Duolingo is a great free resource for learning a language. You might be more advanced than its target audience, but if you're looking for a free tool it's a good start.