Apps like Calibre Documents Provider

Here are some great alternatives to Calibre Documents Provider by Karl Weckworth :
Calibre Sync
Calibre Sync
★3.9
Freda
Freda
★4.8
PDF Reader
PDF Reader
★4.2
EBook Reader & ePub Books
EBook Reader & ePub Books
★3.4
Elsevier eBooks+
Elsevier eBooks+
★3.2
PDF Reader - PDF Viewer
PDF Reader - PDF Viewer
★4.2
Unlimited eBooks
Unlimited eBooks
★4.2
PDF Reader: Ebook, PDF Viewer
PDF Reader: Ebook, PDF Viewer
★4.4
eBook Library: EPUB, PDF, MOBI
eBook Library: EPUB, PDF, MOBI
★4.5
pdf eBook Reader
pdf eBook Reader
★4.1
iPublishCentral Reader
iPublishCentral Reader
★3.6
Bookmate: books & audiobooks
Bookmate: books & audiobooks
★3.4
ePlatform Digital Libraries
ePlatform Digital Libraries
★3.5
Nextory: Audiobooks & E-books
Nextory: Audiobooks & E-books
★4.3
Ebook Reader
Ebook Reader
★4.0
Libby, the Library App
Libby, the Library App
★4.8