What’s the ultimate cheap gadget that is surprisingly useful?

We often talk about expensive phones, laptops, and smart home ecosystems, but sometimes the most useful tech costs next to nothing.

What’s a super cheap gadget you picked up on a whim that turned out to be genuinely useful? Could be a tiny cable management clip, a cheap USB-C adapter, a desk accessory, or some random mini tool you didn't know you needed.

Drop your best budget recommendations below - what is it and why is it worth picking up?