reminds me to get up from my chair quite effectively

Simple.

Awesome app. Please add ability to turn off sound alert. Don't want blast my head while on headphone

When version 4 will appear in addons store?

Simple, neat, effective!
A nice way to track my productivity for the day

I have used this extension for months. It is simple, easy to use, and support desktop notification of fluxbox for both RHEL7 and Fedora 25.

However, recent update broke the stats, thus no statistics.