If you have tried downloading apps from Apple App Store and the following error message is displayed: Account not in this store. Your account is not valid for use in the US, you will need to change the country location of your Apple App Store account.
Change Your Apple App Store Country
Follow these steps:
Go to Settings> iTunes Store and App Store> Apple ID
In the window that opens, click Logout
Reconnect to the AppStore and you will see a message telling you that you'll be directed to the store in your country.
Make your selection and try downloading an application from App Store.