Apple is pretty good at documenting the hardware differences between iPhone models such as the iPhone 7 and the iPhone 7 Plus.
However, I know there are software differences as well that don't seem to be documented. When making my decision to purchase one over the other, I want to consider these differences as well.
Best Answer
One key 'software' difference is the soft-focus capability of the 7 Plus, using the dual camera setup to create an artificial depth of field in portrait photography.
See Two cameras in iPhone 7 Plus allow synthetic zoom, soft-focus backgrounds, usually only obtainable using wide aperture lenses with short depth of field.
Though it requires the dual 28/56mm lenses to make this possible, the actual blur, or bokeh effect is done entirely in software.
This feature alone is what would sway me to the 7 Plus; I've always hated the lenses on mobile phones.