MultiRecs

Try Multi Camera shooting.
Up to three cameras can be controlled simultaneously.
For example, you can preview a telephoto camera, a super wide-angle camera, and an in-camera at the same time, and simultaneously record video and photos.

Available on iPhone XS and later multi-camera compatible devices.
Earlier devices will work as a single camera.
It operates as a double camera depending on the terminal and OS version.
■Triple Camera Supported devices
iPhone 12 Series, iPhone 11 Pro
■Double Camera Supported devices
iPhone 11, iPhone XS and XS MAX, iPhone XR
■Not Multi Camera Supported devices
iPhone X and earlier one
The following two shooting modes are available for MultiRecs.
- Separate mode: Controls multiple cameras simultaneously and outputs multiple files.
- Mix mode: Synthesize multiple camera inputs and output to one file.

In the separate mode, you can tap and drag the preview to move it, or pinch it to zoom in and out to preview it as you like.

● Paid option (full feature option)
MultiRecs is free for most features.
In the free version, a watermark is attached to the photo and an advertisement is displayed in the app.
Paid version, it's no watermark and no more ad-banner.