Ruideng works pretty well. It also shows accumulated mAHr's and mWattHrs.
Dont remember the cost, under $10 USD Amazon.
Been using this for some years now.
You can get a 1 foot USB extension cord with it or longer if you like.
It can show voltages higher than 5v so charging modes that put out 12v will show up as 12v also.
The one thing i dont like about it is the button on the back is far too small, and you have to hold it in for about 6 seconds to get the previous milliampere hour reading to zero out. The reading is persistent so you have to clear it before taking a new reading, but that's only for the accumulated readings if you just need current and voltage you dont have to clear it. But that button bites.
It does have an interesting mode where you can flip the display orientation upside down. That's so that if you have to have it upside down to begin with, you can flip the display and then it reads normally.
I would certainly buy another one, unless i looked for one with more functions, although i dont think i would need much more. It reads current, voltage, milliampere hours, milliwatt hours, resistance, and temperature. I am pretty sure it has 1ma resolution. The rule though is that if you need 10ma resolution then go for at least half that, 5ma resolution, or 2ma even better and of course 1ma even better yet.