I motorbike, and I also have this thing for tiny things…
There are relatively small multimeters, but I was hoping to get a really tiny regular one. I guess the idea comes from very small USB monitors, except I would like to have a universal one that can be clipped in series or parallel (or both) to anything and tell you a few things about voltage and amperage, and possibly a few other things.
Is there one?
Yep, just search on AliExpress, you can probably pick one up for a buck or two shipped.
I wouldn’t trust the amperage ones with the current a motorcycle puts out. But voltage, sure
There are a few highly useful gadgets and toys available today. They aren’t for everyone. The more you learn the less you need. I own and use all of the following, and again, they aren’t for everyone and every situation . Useful gadgets and toys.
Those are nice, I might have to get one.
For around my desk, I have this one: https://www.aliexpress.us/item/3256804870288021.html - it’s decent for the price, and actually takes 21700s while most others I’ve seen don’t (although it won’t take protected 21700, but I don’t use that many of those anyway). Very useful for just organising and sorting batteries. Other than not taking protected 21700, sometimes normal ones with dented positives are a bit tricky to fit, but with smaller batteries you can just use one of simon’s button top adapters to fill the gap.
Also has this hilarious description. I’ve not tried wearing it in my hair yet though, it’s a bit too big and uncomfortable for that 
I was picturing something more like this
All voltmeters should be in parallel with the voltage source.
If you want to go the Amazon route - there are these.
All the Best,
Jeff
https://www.amazon.com/DROK-090554-Ultra-small-0-100V-Motorcycle/dp/B00C58QIOM/ref=sr_1_9?dib=eyJ2IjoiMSJ9.jpVOybAZmMN72hxC7BSv7e_6w6t2-CgST5OdfF4eQanB37jkaVNQMV4F_3z_QSGQARDsiz86tdab2sjhQFnZOFTopd7pRk77mkRPT_Z7lYjpN-M2bw1rakGd61mBrqglEhi7RZtmu3-FWrrWol7_NT8GmDanIkwEhmBTL-kPkFCgM1eUCo-IOIr3i21r07Dz95lY1QkvfPIIMo91wOWqKOyIx8mYXZA77jGH5nEIK1mLj3U8KtBSJlzwZSO802VvaDcMbudv9aJzzLTRphfi05QKXRfChZDCeVIzuAUQIQE.A6oRDirjjnVL5Wt1k3smZm9EQ3H54ki4NYOOqIsoDto&dib_tag=se&keywords=drok+voltmeter&qid=1708806850&sr=8-9
Or a bit bigger
