Owner of 2 pinecils here, there are buttons and a display that shows the current temperature and other stuff. I only just learned that there’s an app, it works more than fine on its own, out of the box.
I got that specific iron because I needed to power it from 12v, and it works very well on the USB PD power supply I already have for my laptop.
Hay is basically cut grass, straw is the part leftover from harvesting wheat and taking the seeds. Both are baled, but they’re used for different things. Hay is food for any animals that eat grass like horses and cows, buy straw is not edible so it’s used as bedding.