App for eye-friendly eBook reading on iMac or MacBook?
What you are asking is impossible, I'm afraid. The Kindle uses a different type of technology for its screen called "e-ink" or electronic paper:

http://en.wikipedia.org/wiki/Electronic_paper

whereas laptops (and iPhones, iPads) have backlit LCD screens.

The essential difference is that the Kindle screen is lit by the light reflected off it - the same as a printed page - this makes it more relaxing on your eye to read.

There is no software way of achieving this on a Mac - you'd need an entirely new screen!

There have been rumours that Apple own some e-ink patents but nothing has come of this so far.