Planning Poker by Standuply - Asynchronous planning poker via Slack task-based surveys
Paco - Never miss a thing on Slack — be more calm and productive
Sprint Poker by Parabol - Remotely bring planning poker to life
awesome - A dynamic window manager for the X Window System developed in the C and Lua programming languages.
Planning Poker for teams - Estimation for agile teams
Lowdown - Lowdown unleashes the valuable content locked within Slack and emails it to your members so they don't miss key information.