The Belkin Lightning audio and charging adapter lets you make the most of the lightning port on your iPhone. The adapter works as a splitter for your iPhone's lightning port, so you'll also have a 3.5mm jack at your disposal. This means you'll be able to listen to music in the train while you charge your smartphone with a power bank. The adapter also supports data synchronization, so you can also transfer data to your laptop while you're listening to music.
Note: This adapter is suitable for iPhones that run iOS 9 or higher.