I viewed a file online and this worked but the file I tried to view is a PDF and it won't show the option for this. I want to download some graded readers to use this feature with, either PDF or ePub. Should it work with all files?
It doesn't work in PDFs yet - honestly, tidy though they may look, internally most of them are horribly messy and we're not yet confident in our ability to link one text block to the next one for continuous reading. (you'd end up hearing a lot of random formatting codes / having the voice jump around randomly to different sections of the page / etc).