The Ultra Wide is what makes 0.5 photos. Phones with one rear camera don't have it. The front camera never shows 0.5x, but can be widened on iPhone 11 and later.
iPhone / Does my iPhone have an Ultra Wide (0.5x) camera?
Guide
Does my iPhone have an Ultra Wide (0.5x) camera?
Short answerOpen the Camera app on the back camera. If you see a 0.5 (or .5) button, you have an Ultra Wide. Most iPhones from iPhone 11 onwards have one, except single-camera models.
About Music Wide Selfie
An iPhone camera app in development for people who film themselves. Not released yet; one email when it is.
One email when the app is ready. Nothing else.