I made Starportal after spending too long in Google Sheets dealing with data quality issues. The concept is to enable your customers to update their customer data directly into your Google Sheet via a secure portal that you can create in a couple of clicks. Starportal magically handles the authentication and makes sure that each of your customers only see the data that is relevant to them.
Hopefully if you have ever had this problem Starportal will help you :)
Collatable