Well, just like the title says : is there any hardware sensors indicator so i can add it to unity's panel?
I only found applets for the older gnome panel.
I'm working on one at the moment (indicator-sensors) which with any luck will be ready in time for the final release of natty - code is barely functional at the moment and still need to figure out a bunch of UI issues, so will be a week or two at least until anything release worthy is finished.
The cpu and memory indicator now supports temperature sensors too. Check indicator-sysmonitor
Psensors has temp indicators.
Add ppa:jfi/ppa to your repositories (or just add nothing if are on 15.04 (Vivid) or later) and then install psensor (and its dependents) in Synaptic.
psensor can show the real temperature values in the top bar only since version 1.0.2 according to http://wpitchoune.net/blog/sensors-in-the-top-bar-of-the-desktop/ (via https://askubuntu.com/a/452501/19753).
That's why one used to have to add an extra PPA to get this feature.
This feature is included in the Ubuntu repositories since 15.04 (Vivid). And earlier Ubuntu releases, for instance, 14.04 (Trusty), has psensor-0.8.0.3 in the repositories (without this feature).
I'm quite fond of screenlets
add to desktop rather than panel though;
sensors screenlets seem nice, there are more similar;
work in unity although possibly not in gnome-shell; need sensors too
sudo apt-get install lm-sensors screenlets screenlets-pack-all