What are some alternatives?
When comparing GoodReader and Google Drive - Docs, you can also consider the following products
FBReader - FBReader is an e-book reader for various platforms. Features:
Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.
calibre - Ebook manager, viewer & converter
PDFelement - All-in-one PDF editor
Amazon Kindle - Amazon Kindle software lets you read ebooks on your Kindle, iPhone, iPad, PC, Mac, BlackBerry, and...
Pages - Pages for Mac is a word processor that offers tools needed to create documents.