Google Drive - Access and sync your files anywhere
Quip: Team Documents for Slack - Create, share and get notified about Quip docs in Slack
Microsoft OneDrive - Secure access, sharing & file storage
Trainual + Slack Integration - Capture knowledge or access training right inside Slack
Cloudfogger - Easy and secure encryption for the cloud. Provides security for all cloud storage services like Dropbox, OneDrive and Google Drive.
DocuExpert - AI powered document processing and review software