Apple has begun offering $29 battery replacements as promised. The company issued the following statement to TechCrunch:
“We expected to need more time to be ready but we are happy to offer our customers the lower pricing right away. Initial supplies of some replacement batteries may be limited.”
Apple announced it would be dropping the price of battery replacements from $79 to $29 after it was discovered that iPhones were being secretly slowed down as their batteries aged. Apple touts the slowdown as a feature but it was put in place to avoid unexpected shutdowns on the iPhone 6s; something that doesn't appear to have occurred as commonly with earlier-generation devices.
Make your genius bar appointment soon, as initial supplies will likely run out. The program is available to impacted users with an iPhone 6 or higher.