If you use Google Drive and want a lightweight Mac client to view and manage your Drive files, then you should check out Archy. Archy sits in your menu bar or dock and gives you one-click access to all your documents stored in Google Drive. From the app, you can easily preview your files, organize them into folders and download them to your hard drive.
Archy also lets you see the current sharing options for files and allows you to share documents with other people from within the app. If you want to edit a document, Archy will open it in Google Drive using your web browser by default. You can also choose an app to open a Google Doc file, which is