PostureMinder от msherringbone

Sitting up straight while at your desk can make a big difference to your posture and overall health.

This simple, elegant extension is easily customizable. Set how often you'd like to see a PostureMinder, then sit back and let it do its work! Useful features include:

== Easy on/off ==
Turn off the extension so you don't embarrass yourself during a presentation.

== Walk reminders ==
In addition to sitting up straight, you should also step away from your device every once in a while.
Set how often you'd like to see a Walk Reminder.

== Snarky ==
Fun, snarky messages will grab your attention and keep you entertained.

==Sync across devices==
Your settings will sync if you have the extension installed across multiple instances of Firefox.