"Enjoy your content on many devices" is one of the headings on the product page. However it does not make clear that although Amazon will allow their apps to be used on non Amazon products they DO NOT allow the Kindle to download Android apps from Google Play.
I have purchased numerous Android apps (such as textbooks in App format) and bought the Kindle Fire HD thinking I could transfer my apps from Google Play but Amazon do not permit this. The apps I need are not available in the Amazon app store. Had I known all this I would not have bought the Kindle Fire HD. As it is I am now stuck with it as I've opened the packaging and used it (I bought from a high street retailer) but it is not fit for the purpose I bought it for.