Is there any live demo available for this project ?
Not that I know of, it actually looks really easy to use based on the documentation posted. When I get some free time I will set it up mess around and post my findings/instructions.
Edit: Spending my lunch looking at this, so far you need a chain.com api key (temporarily) eventually they said you will be allowed the option to let your own bitcoind node verify what they have the chain api doing. You need to connect to a bitcoind node, and it looks like this code only runs currently on Linux in my testing (Haven't tried OSX probably works fine). Right now I am setting up a new Debian VM with the latest bitcoind and the blockstore stuff to see if I can make a record.