Strangely, it did support Greece (or so it said), but it doesn't seem to handle transfers very well, giving me no way to fly from Athens to the Newark.
I'm going to rate this tool a solid 1/10.
It's 2012. A US-only service when there are TONS of international alternatives?
Second, intentional coverage just goes with the domain for a flights application. Are Americans supposed to just switch back and forth to some competitor for non domestic flights?
I use Skyscanner here in Europe for regional and international flights, however really the prices are only useful as an indication. For example, one flight I found the cheapest option was Ryanair, but when I actually booked it the price was €10 cheaper than listed on Skyscanner.
http://www.bbc.co.uk/news/business-18718556
Also last month they were forced to remove the 'you have to pay €12 to pay with a Visa card' policy, so now the fee is 2% for all cards. However, they now make the admin fee mandatory however you pay :)
http://www.thisismoney.co.uk/money/holidays/article-2240292/...
Add on the baggage fees, landing fees, priority boarding fees, tax, credit card fees, etc. and the price isn't so impressive.