Apple and LG are partnering on a foldable iPhone planned for 2020, if a report out of Korea is accurate. With the two companies have partnered on iPhone components in the past, it seems like a plausible response to Samsung's plans to launch a foldable Galaxy Note next year.
https://www.notebookcheck.net/Apple-could-release-a-foldable-iPhone-in-2020.258048.0.html