Finally after more than a year trying searches, waiting, being alert while surfing I found a little software pearl for helping me control my rests on computer.
The name is Workrave:
http://www.workrave.org/Open source, free (of charge) and for Linux and Windows.
It is configurable and gives some statistics of your computer usage. Plus there is a portable version on
http://portableapps.com/news/2011-02-03_-_workrave_portable_1.9.3_released, that was how I discovered it.
And the program description helped to unveil the right keywords on Google to search this kind of software. I had rough ideas for keywords but they never showed up what I was looking for.
It has all the options I really wanted and others I found really useful as well.
So now there isn't excuse for not taking a walk and rest your eyes.
![Tongue :P](https://www.omnimaga.org/Smileys/classic/tongue.gif)