It looks like the first Kickstarter was to find and test an adequate filtration system, and the second is to build a "float lab" test pool. If that succeeds they'll probably have to launch yet another Kickstarter asking for funding of over a million to build the final product.
The Kickstarter ended in 2011, and their web site at http://www.pluspool.org/ has options to buy tiles. It looks like they've pursued other fundraising options after Kickstarter.