https://www.theregister.co.uk/2017/08/23/microsoft_deflates_gigjam/

Microsoft has spontaneously and ephemerally killed GigJam, a collaboration tool it billed as empowering “people with a co-working mindset” to “spontaneously and ephemerally involve others in your work.”

Redmond only revealed the GigJam preview in June 2016, promising it would soon become a new member of the Office family and enhance the suite by letting users share short snippets of documents on mobile devices.