@Sweder It's built into iOS 5. Text someone else with an iPhone and message turns blue, indicating it's sent for free.
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
@Sweder It's built into iOS 5. Text someone else with an iPhone and message turns blue, indicating it's sent for free.