Free Zone, accessible through the g.co/freezone domain should work with almost any internet-enabled phones (mainly featurephones). It's not optimized for smartphones, but should work on those as well. There are some simple rules to using Free Zone: everything is for free, except for clicking a link that goes out of Google+, viewing an email attachment or clicking a link that's found on a webpage that has been a search result. That last one means that when you've done a Google search, you're free to click on any result you like, and you won't be charged for that. But if you have clicked on, say, result 3, and then you click on a link that's found on the webpage of result 3, then data charges will apply. Thankfully, each time there's danger of being charged for data traffic, there will be a pop-up warning.
Obviously, this service requires Google to partner with a lot of carriers around the world, its roll-out won't be very quick. And, as we said, it's designed for emerging markets, so it's likely that it won't come to the U.S. or Europe. Free Zone has just launched in the Philippines with the carrier Globe. If the service turns out to be a success, Google will probably expand it to other locations as well.
source: Google via Reuters