Here is an iPhone 7 accessory that lets you take your smartphone underwater to capture all the action. LenzO is rated to a depth of 10 meters. It has color correction features and lets you interact with your smartphone without having to take it out of the case. It also has dual tripod mounts.
The LenzO for iPhone 7 floats, so you won’t lose your phone easily. You don’t need any specific app to start recording underwater with this. Yet another cool Kickstarter project.