I just opened my Amazon Kindle publishing account now... however,I'm half way there because I haven't provided my billing information due to a little issue with my bank account. but I want to know, what tools are advisable to help with writing your books offline. are the books written and edited on the Amazon Kindle publishing account,or you need another app to design and insert the book cover,write the book and then Amazon handles the publishing?? if such is the case...what tool do I use to start the writing?