Sitebulb has a range of 'global settings' which act as the default settings for every new audit you start. From the top navigation menu, choose the 'Settings' option.
From here, the 'Google Accounts' tab allows you to see which Google Accounts are currently authorised to collect data using Sitebulb.
There are two things you can do here, by clicking the respective button:
Delete your Google Accounts
If you click Delete, you will be shown a warning box overlay, which tells you how many projects currently make use of the authorised account, along with a few example projects.