Planning Poker by Standuply - Asynchronous planning poker via Slack task-based surveys
i3 - A dynamic tiling window manager designed for X11, inspired by wmii, and written in C.
Sprint Poker by Parabol - Remotely bring planning poker to life
dwm - dwm is a dynamic window manager for X. It manages windows in tiled, monocle and floating layouts. All of the layouts can be applied dynamically, optimising the environment for the application in use and the task performed.
Planning Poker for teams - Estimation for agile teams
Openbox - Openbox is a highly configurable, next generation window manager with extensive standards support.