Quip: Team Documents for Slack - Create, share and get notified about Quip docs in Slack
Workflowy - A better way to organize your mind.
DocuExpert - AI powered document processing and review software
Graphite - Graphite is a highly scalable real-time graphing system.
Trainual + Slack Integration - Capture knowledge or access training right inside Slack
BaSalt - Blockchain based documents managing/sharing platform