Is that supposed to be the size of the block chain? If so, you might want to rephrase the label?
That's the amount of free disk space left on the node, so basically "the amount the blockchain can grow before I run out of space". Purely vanity and has no real purpose - but as with most things, can be controlled with a toggle switch in config.
I got the script for making graphs sent to me by Shorena, I could make it available if others want it too. Not sure if Shorena already made it available.
The graphs look nice, though I guess it's beyond the scope of this app for the moment - would be nice for a 2.0 release though! Would be interested to see what the code to generate the graphs is like - if you can check if Shorena is happy for the scripts to be made open source (a pre-requisite for the project) that would be awesome
It is possible to check your node on the leaderboard to see how you fare.
Nice, I may add this in future