A free program for Android, by Isomer Programming LLC.

Picture Blend is an app that lets you combine multiple photos into one. 

Simply take multiple photos from your camera or gallery, and combine them into a single image. The process is as easy as taking pictures and selecting the blending ratio.

It offers multiple options for saving and sending your results. You can save the final image to your device or to the gallery. You can also send it via email or another app.

The program offers a black background, which makes it easier to blend the pictures.

Picture Blend supports both the front-facing camera and the back-facing camera on your device.