Zao Jing Plan is a free iPhone application developed by Jian Song Su. It falls under the category of Utilities & Tools and offers a range of features for video editing and image manipulation.

With Zao Jing Plan, users can add watermarks to their photos and videos, including text, images, and even mosaics. The app allows for easy adjustment of the size, color, and other properties of the watermark, ensuring it blends seamlessly with the original content.

In addition to watermarking, Zao Jing Plan also offers video resizing capabilities, allowing users to crop their videos to various sizes and aspect ratios. This is particularly useful for social media platforms that have specific video dimensions requirements.

Furthermore, the app provides the option to speed up videos, enabling users to play them at different speeds. This feature is perfect for creating engaging short videos for sharing on social media.

Lastly, Zao Jing Plan offers a unique feature called "Nine-grid Screenshot," which allows users to crop their images into nine separate pieces. This creates an eye-catching effect when posting on social media platforms, making the content stand out.

Zao Jing Plan is a versatile and user-friendly application that provides essential tools for watermarking, video resizing, video acceleration, and image cropping. It is a valuable addition to any iPhone user's app collection.