Tap a piece
One without the other is a doorbell with no wiring.
A pair, not one piece
By itself Termux is a tiny Linux computer.
Termux:API lets that computer use phone features: battery, clipboard, flashlight, notifications. You need the app from F-Droid and the termux-api package inside Termux. They work as a pair.
This page is the explanation. Install the pair on Stage 2. First use it in the battery workshop.
A menu, used one at a time
Battery, clipboard, flashlight, notifications. Named so you know they exist. Used when a project asks. Camera and location wait.
termux-battery-statusNext step
nano is the first editor. Ctrl+O, Enter, Ctrl+X.