While Google has baked in its own device backup/restore tool into Google Play Services, OnePlus is offering its own migration tool with the new OnePlus Switch app. The app can help you migrate contacts, SMS messages, call logs, calendars, photos, videos, audio, and apps (but no app data). It can work on any Android device that runs Lollipop 5.0 and higher. The app is currently in beta, but OnePlus says a stable version is expected to arrive mid-January.
Source: Android Police