This is a simple effect; it enables the image to be rotated to align with the horizon. It also allows you to flip the image vertically or horizontally.
Use the slider to adjust the angle of the rotation. The H-Flip and V-Flip features allow you to flip the image horizontally or vertically.
The H-Flip box has been selected here, so that the image is flipped horizontally in the time lapse software preview window.
Note: this effect is available in the free version of Time-Lapse Tool.