To see the breakdown of usage in your Google account, go to https://drive.google.com/settings/storage
To see all the files in your Google MyDrive sorted by usage, go to https://drive.google.com/drive/quota
To see the usage in your Box account, go to https://berkeley.app.box.com/account, then scroll down to "Account Details" and look for "Storage Used"
Usage by SPAs
To see the usage in a SPA, log into Google or Box as that SPA, and then follow the links above.