Details about the permissions required by

During you first visit of some permissions will be asked to let you access the application

This article will give you details about them.

View basic information about your account and View your email address

These permissions are asked to let the application identify yourself.
Once connected, you will see your email and your profile picture in addition to a menu which let you access to your Google Profile 
on the top-right corner.

Don't worry, we will never mess-up with your email!

Add itself to Google Drive

This permission will install in your Google Drive to let you open and create document from it.

View and manage Google Drive files that you have opened or created with this app

This permission is asked to let you open previous directly from the application (without having to open your Google Drive).

This permission doesn't allow us to get informations about other files stored in your Google Drive.

Perform these operations when I'm not using the application

This permission is required by default by the Google Drive API to avoid request authentification each time you are using

In addition, you can find information about these permissions on the Google Drive SDK website:

Feedback and Knowledge Base