supports formats: FB2, EPUB, MOBI, RTF, DOCX, HTML, MHT/MHTML, Webarchive, CHM, TXT, CBZ (comic book ZIP) and PDF;
if PDF file has a text layer, the text will be interpreted and the book will be formatted as a text one. If not, it will be opened as a set of regular pictures, like it's done for comic books;
can open audiobooks of MP3, M4A and M4B formats;
import from local devices, iCloud, Dropbox, servers connected by SMB protocol, as a single book and as a batch;
an ability to create internal shelves structure, with search/filtering by genres and keywords;
full-text search of all the library contents, together with the notes created;
an ability to translate (even when there is no Internet connection) selected words and phrases to the chosen language;
reading the text aloud (even when there is no Internet connection) with different variants of speed and operating from the media control;
an ability to correct typos quickly;
bookmarks and notes, ability to export the latter as a file;
an ability to directly download books from servers that support OPDS.