I need to find applications for particular formats of books:
1) ePub - Cool Reader, Ideal
2) Daisy - Darwin Reader
3) Txt - Accessible Talkback Editor
4) PDF- Adobe Reader, Smart Q Reader
Application with Reading Granularity Support for blind or low vision users from external keyboard- Page, Sentence, Word and Sentence level selection of text while reading.
There is no app which is clear or has documented the external keyboard usage for blinds or low vision users, except Accessible Talkback Editor none on the app has a clear UI/Documentation to suggest the Granularity selection.