Project Bongo: An In-Depth Overview of the iPhone 15 Pro’s Canceled Haptic Buttons With the introduction of the iPhone 15 Pro on September 12, Apple omitted one of the most innovative features and ambitious undertakings initially planned for the device – haptic volume and power buttons. As the iPhone has evolved, Apple has periodically improved vibration technology. In 2011 with the ‌iPhone‌ 4S, Apple began using linear reson…