Good healthy habbits its a modification of xlock simply blank screen for 5mins(default) on every hour
In order to build hlock you need the Xlib header files.
Edit config.mk to match your local setup (hlock is installed into the /usr/local namespace by default).
Default take 3mins break on the hour BREAK_DELAY(Default) = 3(mins) BREAK_INTERVAL(Default) = 60(mins)
Afterwards enter the following command to build and install hlock (if necessary as root):
make clean install
Simply invoke the 'hlock' command and take a walk, there's no getting out of this one.