Pokemon Go just recently went live in both Android and iOS. But unfortunately it is only available in Australia's Play Store and App Store. \
Here are the following steps to install Pokemon Go on your device if you are outside Australia
For Android Users (No rooting required):
1. Download the APK from the link provided. Link 1, Link 2, Link 3
2. Run the APK from your phone and start your journey to become a Pokemon master!
For iOS Users (No jailbreaking required):
1. Go to Settings > iTunes & App Store > Apple ID > View Apple ID
2. After entering your password, go to "Country/Region" and then choose "Change Country or Region"
3. Select Australia from the list and leave the payment method blank.
4. Go to the App Store and download the game!
UPDATE (7/6/2016 21:00 GMT+8):
Currently the game is region blocked outside AUS/NZ. The only way to play the game is to use a VPN(free or paid) and have it routed to the said countries. Game will still run but you wont be able to catch pokemons or as well see pokespots or gym places
