Shimano has been in the electronic shifting game since Dura Ace 7970 was introduced in 2009. Their E-Tube system debuted with Ultegra 6770 in 2012 and continues to be the standard in electronic shifting systems today. You had to take your bike to a local bike shop that had an expensive adapter and computer program to tune the drivetrain and update firmware.
Since then, Shimano has released the E-Tube app for iOs. By adding some Bluetooth Low Energy components to your drivetrain, you can update firmware and tune your shifting from your iPad. It's never been easier to tune and update your Di2 system.
Click through the jump to learn what you need to use your iPad to tune your E-Tube Shimano Di2 system, including a video overview of the app and how to use it.