Affiro by Patrick Stephen

Affiro's primary feature is watching the key inputs of a user and producing a signature from them, which can be uploaded with a document to app.affiro.com to verify a document was produced via those key inputs.

Users can authenticate to app.affiro.com as well, which adds some background services to automatically support detection of documents and classrooms on google docs and with google classrooms. This information is stored encrypted.

Source code is open here: https://github.com/sandgardenhq/affiro-browser-extension