I'm not 100% sure that this can be described as 'computing stuff', but it's certainly related. It comes under various descriptions, but one of the most common designations is LCR-TC1, and it's variously referred to as a Multi-Function Tester or Transistor Tester. I just got it, although I ordered it a few days ago.
If you plug any small electronic component into it, it will determine what it is, and give you the basic parameters for it. It seems to be able to identify single cell batteries (no more than 4.5V), capacitors, resistors, inductors, diodes, zeners, bog-standard bipolar transistors, thyristors, triacs, JFETs, MOSFETs and IGBTs.
You can probably buy similar unit, without a case or battery, and with a B&W screen for as low as £7 from China, and if you're willing to wait you can get this one with an internal USB charged Lithium cell and case probably for £12 on Banggood, AliExpress of eBay. On eBay, I paid £15 with about 1 week delivery to Argos Click'and'Collect). Now I know what to search for, they are also available for £18 on Amazon, with Prime next day delivery!
It's not terribly accurate, especially with some of the slightly more exotic parameters, like a capacitor's ESR, but certainly provides approximate values. If you want to measure a zener, with a reverse voltage greater than 4.5V, there's a pair of special connections for that, which will supposedly work up to 30V, although it failed to measure a 29V Zener in a YouTube video I saw (but did work with a 20V Zener).
I've tested it on a few random capacitors and resistors, and it generally gives a value within the quoted error range of the components, and happily identified a MOSFET, although it measured an R
DS variously between 0.2Ω and 0.4Ω, when the datasheet says a typical value of 0.065Ω and maximum of 0.075Ω. However, for a unit costing £15, I didn't expect a great deal of fidelity! Internally it's relying almost entirely on an AVR microcontroller for the measurements, and the ADC on that is optimistically only 10 bits typically over 5V, so naively that's resolution of 5mV, but I suspect other factors affect its ability to measure some parameters.
Quite a cool, neat little gadget.