I think it'll be a good substitute to sending images/documents in email if restrictive retention policies are required for legal reasons at companies.
Also, it's great for collaborative mockups with remote designers to send edits to the DOM back and forth.
The hardest technical challenge was to get the browser extension to work on many different sites, including those with different http/https protocols, and with restrictive CORS and CSP policies.
Sharing here to collect feedback to improve. Looking forward to any!