Low Power Mode is a great way to save battery life when you know you aren't going to be able to charge for a while. It stops automatic downloads and background app activity like iCloud Photos, reduces some visual effects, stops email fetch, applies auto-lock faster and does a bunch of other things all aimed at reducing battery usage. iOS 14 allows you to customize your Low Power Mode (and charging mode) by adding more settings through the Shortcuts app.
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.