Nook with the Kindle App

I have a Nook HD+ and am very pleased with it. However, my BIL uses a Kindle. At last count, he has a good 2,000 books on his Kindle and he's very willing to share them with me, to loan them to me to read. If I download the Kindle App on my Nook, I'll be able to download and read the Kindle books through the Kindle App? Correct?

If I download a book through the Kindle App to read on my Nook, do I have to create a bookshelf just for Kindle books on the Nook? That way, it's not in with my Nook books and I wouldn't get confused as to which books are Nooks and which are Kindle books. Would that work to keep them separated?

Any hints to download or to work with the Kindle App? Can I do this and will it work OK?

Never mind....figured it out.

Good because I wasn't sure how the lending thing works.    I have a kindle, a kindle fire and now an iphone with the kindle app.  Reading between the devices is simple and straightforward; but I've not done the lending thing.