Files for Google™ Drive is the best app for managing/downloading your Google Drive, designed from ground up for
Kindle Fire only.
Just login your Google account, you will see all your Drive files right away, all well sorted. Your folders,Starred,Recent,Shared with etc.
You can download any number of files for offline viewing, and even open with third party apps like Quick Office.
Files is a super fast native app, not web app.