The O2 App is a tool for you to have an easy and quick way to manage your data usage. It allows you to track and manage your O2 data usage for calls, SMS, and data. It will keep you informed about what data you are using and when you are using it. You can also use the O2 App to buy additional services, such as the Smart Travel Insurance, which is a service that allows you to buy insurance in the event of loss of or damage to your mobile device while you are traveling. You can also use the O2 App to buy additional services.