I heard about Seeing AI and gave it a try. It runs on iOS, and is phenomenal. If you or someone you know has low vision, it should be very helpful.
Aside: has accessibility been covered on MPU?
Edit: a little more detail:
Speaks text as soon as it appears in front of the camera
Provides audio guidance to capture a printed page, and recognizes the text, along with its original formatting
Gives audio beeps to help locate barcodes and then scans them to identify products
Recognizes friends and describes people around you, including their emotions
An experimental feature to describe the scene around you
Identify currency bills when paying with cash
Generate an audible tone corresponding to the brightness in your surroundings
Describes the perceived color
Reads handwritten text