I have come to the same conclusion about exploring existing texts for trim sizes. (thebookdesigner.com)
It's kind of like iBooks Author for Apple and iTunes U, but it uses PDFs of existing texts as a starting point and offers over-the-top digital features for Kindle - based consumption. (techcrunch.com)
However, for the end - user, there are several third - party applications that advertise the ability to backup existing text messages from these devices. (slaw.ca)