I'm not too much into gadgets, but this is my favourite one. It's a spring hammer to make leading holes. If you're doing a lot of metal working, this gizmo is near indispensable.
@neauoire those are great! I got one years ago to set proud finish nails flush when I worked as a painter. I got another one recently that is designed for removing hinge pins - It has a wide end and I use it as a little hammer.

@neauoire Neat!

On a related note, i do recall finding a very cool fastening tool, called a wire clamp: https://youtu.be/mRc7ZDRcgrQ

I don't see many people talking about it in the DIY space, but I do find it elegant

The Clamper | Old Tool Reborn

YouTube
@neauoire cool! I never saw one before. In italian it's called BULINO AUTOMATICO A MOLLA 😄
@neauoire
I heard of it not long ago. I'd love to get one. Now im using a car valve that I sharpened out, but that looks way fancier.