Backup and Sync replaces Google Drive and lets you upload and manage your files on the cloud.
ZIP Extractor lets you extract files from your archives to your Google Drive storage.
Open Drive is a GUI client for Google Drive that lets you sync your files and folders to the Drive from your machine.
SaveToDrive allows you to upload files from the Internet to your cloud drives without requiring you to first download files to your computer.
Pouch lets you access your Google Drive from the bookmarks bar.