Though is suggested to improve Rc to read excerpts from books or magazines such as The new Yorker or The Economist, these have drawbacks:
- are not free of charge and cheap to subscribe
- maybe are too tough and require skills that not all students have or are far from the concepts related to Gmat
- are not so fun to catch your will to read
- having a reading fast and userfriendly on your laptop or smartphone (maybe an android

)
Instead here I suggest you the best resources that you may find to fix the aformentioned points.
BEST RESOURCES
Each site has its feed RSS; you could put them in your Feed Reader. I use the best at the moment; it is another level and experience to read this good stuff.
App for both iOS and Android.
FeedlyHope you like my effort to improve your RC skills.

Thanks for sharing this list.
Thanks.