If I buy a book from iBooks, can I download it also to my Kindle, so I can read it on my Kindle and my iPad?
There was a similar question asked here : http://www.makeuseof.com/answers/open-ebooks-bought-ibook-store-kindle
you can read that,
Books downloaded from the iBookstore can be placed on up to five devices you own that you’ve authorized with your iTunes Store account.
if your books are DRM free but not in a kindle compatible format, you can convert it with format using :
Kindle app is for reading books from amazon, and not applies to the reverse situation , we have here.
I found this one: http://www.ipad-transfer.com/epub-converters/convert-epub-to-kindle.htmlConvert ePub to Kindle - Amazon Email Service
document via email to your primary email address (firstname.lastname@example.org).
The documents will be sent back to your personal email address. You can
then transfer the documents to your Kindle via USB. For the latest
Kindle models, you can have the documents delivered to your Kindle via
you will have to remove drm if it is not drm free.
If you buy books on iBooks, they will be in the EPUB format. You can't put these files on your Kindle, but you can convert them to MOBI, which you can. To do that, you can use something like Calibre for example.
There's also a Kindle app for iPad, like Jeff Fabish mentioned, but that would be helpful if you buy your books for Kindle and want to read them on your iPad.
Let us know how you fared!
You can't convert iBooks' EPUB format to MOBI because those purchased files have DRM. While Amazon's MOBI DRM has been compromised (so easy conversion tools now exist,) I don't believe that is the case with iTunes' iBook format.
On your iPad, install the Kindle application.