I would expect a tutorial such as this application to be near flawless since it proposes to be a guide to English grammar. Instead, it is a near perfect example of poor grammar, sentence structure, and a general lack of grammar skills.
Nearly every page contains grammatical errors ranging from missing articles to nouns that should not be capitalized since they are not proper nouns. The other sections on verbs, adverbs, adjectives, and conjunctions are equally flawed.
All in all, this is a very poor resource for learning English and grammar. I would recommend that Eknath Kadam remove this application, return to school, and if serious, correct all of the grammatical errors in this application prior to posting it on iTunes again.
I have purchased a few other of the apps and expect that they are just as flawed; however, I will give them the benefit of doubt and rate them separately.
My overall recommendation is DO NOT BUY THIS APPLICATION!