Sortd - Rated the #1 App for Gmail
Kubeless - Kubernetes native serverless framework
KanbanMail - A Kanban board for your emails.
Supergiant.io - A datacenter management system built on Kubernetes
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
LastBackend - Lightweight Kubernetes replacement