ElnurYou can use E-GMAT for building up the concepts , there is no doubt about that. But if you are looking for other sources to prepare you should try Power Score CR Bible.
I have used both Power Score bible and E-GMAT CR, but i felt i gained more from the bible than the course.
But when it comes to practice its always better to stick with official questions. You can practice CR questions from latest OG and Verbal Review books and also old official questions from previous versions of OG which are available in GMAT Club. If you want to practice questions apart from OG you can try LSAT.
All the best for your preparation.