iOS 14's Back Tap is an accessibility feature that literally lets you tap the back of your iPhone to access system features or start shortcut automations. For example you could assign your App Switcher to the double back tap, letting you open your App Switcher simply by tapping the back of your iPhone two or three times. There are a bunch of system and accessibility features available for Back Tap, including Control Center, Home, Screenshot, Magnifier and Zoom among others, but Flashlight is noticeably missing.
The Shortcuts app for iOS lets you program a several step routine that uses multiple apps into a "shortcut" that requires just a tap or two. For instance, you could use the pre-written shortcut Home ETA to send your ETA to your significant other when you are on your way home, reducing to a single tap a process that would normally take finding your ETA with Maps, then composing a text message.
A lot of people like to (or at least used to like to, before they started using smart phones as alarm clocks instead of good old clock radios) wake up to a local news station to hear traffic, weather, sports scores and more, or to their favorite music station. Since your iPhone is capable of tuning into just about any radio station you'd think there would be an option to have the alarm automatically tune to one of your choice.
Shortcuts is Apple's new version of Workflow that launched with iOS 12. It is a productivity tool that does what its name implies - each shortcut is basically a program or 'workflow' that runs through a set of steps to produce a desired result. For example, Home ETA is a navigation shortcut that uses Maps and Messages to send someone (pre-determined by you) your arrival time with a single tap.