[Gremlin]

I bought the one Margaret suggested a few weeks ago for my cleaner, she doesn't drive therefore she can't charge her phone driving between jobs.
She was very impressed with it so I bought one for myself.
There may be a time I need it when I'm not at home or in my car.
They are very light and take up hardly any space in a pocket and I'm sure they would be easier to cart up a mountain than any fancy gadget.
If making an electronic device for educational purposes was the aim, well done lad.