Keera Posture: when Haskell, OpenCV & Simplicity unite

Yoga with lambda

Can we show how powerful Haskell is with an application that is very useful and, at the same time, surprisingly simple?

I present Keera Posture: a program that will warn you when you sit or stand in a straining position. All you need is a webcam and a PC.

Here’s how it works: When you start Keera Posture, it will silently dock in your traybar (Windows) or panel (Linux). Just sit correctly, right click on its tray icon and select ‘Calibrate’. From that point on, Keera Posture will play a subtle sound when you are no longer sitting in the same position, effectively warning you when you slouch or hunch. You can also enable an overlay warning screen, which may be more suited to environments where sound may bother other people or where no speakers are available.

The program is fully configurable. You can set the webcam you want to use (when more than one is available), change the notification delay (the time you have to sit incorrectly until you are warned) and the sensibility (how much you have to move to be notified). Available in different languages.

Note: The text of this post is distributed with All Rights Reserved. The image is based on a picture by Grand Velas Riviera Maya, located here:, which is distributed under a CC-by-sa licence. The Keera Logo and the Keera Posture composition are fully copyrighted.