"海外スマホ利用" is a travel and navigation application developed by KDDI CORPORATION for iPhone users. This free app allows users to conveniently access the "au海外放題" and "世界データ定額" services while traveling abroad. With this app, users can use their smartphones in over 160 countries and regions just like they do in Japan. By pre-booking the "au海外放題" and "世界データ定額" services within the app while still in Japan, users can enjoy cost-effective rates during their travels.

The key features of this app include the ability to pre-book the services while in Japan, check remaining usage time and start using the services upon arrival in a foreign country, a guide on how to use the services, and display of Ministry of Foreign Affairs safety information and useful tips for the travel destination.