Made by Montage is a free Android app with tools for creating a montage or photo collage from your images. The trick here is that rather than simply comibining full images into one piece, Made by Montage utilizes an Autocut tool and layers to remove elements from other photos and place them on another.
Undo and eraser/un-erase features are available, images (and parts of images) can be rotated and adjusted. When you're finished, you can share the montage to social media or via email. Made by Montage promises no ads for this free app, but your image will have a "MadeByMontage.com" watermark embedded in the lower portion of the finished creation. But, depending on the image, you may be able to crop the photo to eliminate the identifying mark if you'd like. (Please note, however, that we do not endorse cropping out photographers' copyright from images — ever.)