Following closed beta tests, it seems the new Pokémon GO is now live on Android (no updates yet for iOS). But reports have surfaced that it currently only works in the U.S., Australia, and New Zealand. Nintendo's augmented reality-based game has been made in collaboration with Niantic Labs and allows you to collect, train, and battle Pokémon in the real world. It’s a free-to-play game with in-app purchase options as well as a Bluetooth accessory that’ll alert you of Pokémon and let you capture them without bringing out your phone. It may not show up for you yet but with this bit of news swirling around, you should expect to have the app ready for your phone in no time.
Source: 9to5Google + Android Central + Fev Games + GameSpot
UPDATE (as of 9:49 p.m. EDT):
The game is now also live on iOS in the same areas and it's also already available in Japan as well.
Source: Nintendo Insider