Access to the square image feature in iOS would be great.
The results of fitting a rectangular image in to a square container are not desirable. You either get wasted container space or missing image details. You must also later process all the images and crop them to squares then put them back into containers. Even if post processing is part of standard workflow the cropping of every image is a step that could be skipped if the square camera is available.
All of the FM sample files and most peoples solutions use square containers for images on layouts. Many web applications are primarily using square images now. With the common use of square containers on layouts it makes so much sense that this should be available. From a users perspective it allows you to capture what you need to see in the container correctly the first time without having to crop with your mind eye and take a few photos to get it right. Watching users deal with this is painful. I have seen some users add masking tape to the edges of iPads to help them get photos centered properly. From a data perspective the images can be smaller sizes.
Sizing an image to fit and having wasted container space is a very sloppy way for any developer to allow a solution to look.