Default App for taking similar pictures using reference from previous picture

So i am hoping to find a camera app that will help me take near identical pictures each day. I am doing a weight loss challenge with some friends and want to take a picture each day and be able to string everything together into a video showing weight loss over time.

I can do my best to stand in the same place and snap a pic. But ideally I would like to be able to overlay yesterday's pic with transparency in a camera app so that I can have a reference point for distance, position, zoom, etc. For the next pic. Basically so that whoever is taking the pic can line up the daily pic with the exact position of the previous pic by overlapping the real image with yesterday's image..... Hopefully I'm making sense.

I've been searching for an app that will let me do this. Does one exist? or one of you bright people out there could write one and make $0.99 of of me. Any thoughts? Much appreciated!