The Samsung Galaxy s9 supports 960 frames per second slow-motion video recording. Just keep in mind that it only works with HD resolution. Yet the difference between 240fps and 960fps is significant as see on Samsung's website.
I actually got a chance to play with the super slow-motion feature in a shopping mall in Seoul, South Korea. Samsung put an air-driven container with balls inside. When you push the button, the air makes the ball move at a very high speed within the container. You can then use the Galaxy S9 to capture a video of those moving balls and see how it looks when playback after recording the scene at 960fps. It's amazing how sharp and beautiful that rendering looks. It's great for capturing funny short moments or interesting scenes that you can only notice the fine details of their movement if you shoot it with a fast frame rate capable camera, like the S9 rear-facing camera. A great feature.