Built out of sheer frustration.
I'm a CFO, and our Xero organisation held over 50,000 contacts. Xero was painfully slow, and holding all that historical personal data was a privacy-law problem we couldn't keep ignoring.
Cleaning it up was impossible. The database was too large for Xero to export, and Xero caps contact updates at 998 rows per file. That meant more than 50 manual spreadsheet uploads. Xero support's own advice was to go find a third-party app.
So I built it with my partner, an enterprise architect: an app that handles enterprise-scale data properly, and now we're sharing it with the Xero community.