While creating campaign you can select targeting options: country and android version.

App2top detects user country based on ip address, google play based on payment address (if user did not add any payment method, google uses registration ip address to determione user country).

You can select target countries from the list:

DAU - daily active users.
Other - means all other countries.

Check the image below, current (11/06/2017) users statistics by countries:

OS versions (11/06/2017) users statistics by android versions: