Have you bought a 2018 iPad Pro, then your choice of stylus options is about to go up by one: the Logitech Crayon device will be supported by the premium tablets when iOS 12.2 arrives, which should be next week.
The news isn’t official yet but was revealed by Nilay Patel on The Vergecast having previously been hinted at by Jason Snell at Macworld. According to AppleInsider, the stylus doesn’t work with the 2017 iPad Pros.