In mobile Shake, select the Add button below. Select the Shoot to upload video option. In the Add video field, crop the video and go to the next step. Open the "Effects" property at the bottom and find the Split Screen option in it and click on it. In the Split Screen column, there are many kinds of split screen effects, choose the right one according to your needs, and then click Download. When you use it, you need to press the button option bar without letting go, so that it will add special effects to the video. Select the desired split-screen effect, and then click the Save button above to save.