This program is a software for merging two images. You can overlay political and relief maps or inserting a watermark in your pictures. Flexibility in alignment of the images such as scaling, relative positioning and rotation is supported. It includes edge fading to remove edges seen as a result of merging two images of different sizes and positions.

S_MERGE is a feature-rich tool for merging up to 8 images or text. Useful for overlaying political and relief maps or inserting a watermark in your pictures.
Total flexibility in alignment of the images such as scaling, relative positioning and rotation is allowed
with many options available for blending the images together.
Apply invidual image options such as cylindrical panoramic projection, overlaying a dotted and/or a solid line grid on to the image, pincushion/barrel distortion correction, skewing and trapezoidal distortion.
When all done save all of, or part of the image to a file.

The license of this software is Free Trial Software, the price is $24, you can free download and get a free trial.