EPUB reader for Android
According to the Code Conventions for the Java Programming Language, 9. Naming Conventions, I'd call the class EpubReader. The name should be a noun, and try to avoid abbreviations which makes the code harder to read.
Couldn't the readEpub method be private? Why has it default access?
The readEpub does not use the epubInputStream parameter. Why is it read sample.epub? It looks like a test code. Furthermore, this class seems really incomplete. onCreate creates a new Eread instance then calls its readEpub method. The readEpub creates (again!) a new Eread instance (epubReader) then calls its readEpub method. It's an endless loop.
onCreate is an instance method, so you could call readEpub without creating a new Eread instance:

Book book = readEpub(epubInputStream);