This whole 'lost the button" really didn't bother me all that much. What bothers me more about the whole process was the need to create another icon on my iPad's home screen. Then, having to leave the Kindle app to buy a book, should I need to browse the store.
Yeah, I know, what a hardship! But, it's the principle of the thing!
So, I create a .mobi book with web links to the Amazon home page, the Kindle store, and to the e-books, magazines and newspaper stores. I created it in Word, saved it as html, put it in Calibre and then converted it to mobi (with my own cute little cover, even!).
I then used Dropbox to "Open In..." the mobi book in my Kindle (my Calibre library is on Dropbox ... but you could always just e-mail yourself the book and use "Open In..." that way). Or use iTunes...
So, now the book is on my Kindle app's Home page. When I open it, I am presented with the web links. I press one and the
Kindle's web browser opens. I can browse all day long or purchase books. When I am finished, I press the blue Done button and am returned to the Kindle app/my mobi "book."
Much better than putting yet another icon on my already crowded iPad home screen and constantly having to switch between the Kindle and Safari apps. As usual and as always, YMMV.
Marilyn
P.S. If you want a copy of my book (it's free!) - PM me and I'll provide you a link to it within my Dropbox's public folder.