
I had several USB voltage/ammeters but needed something that could track how much current was being transferred because I thought the battery in my phone was running low. It does exactly that, I was able to find out that my battery is about half of what it should be, it's an old phone after all. This can also be useful for checking USB battery capacity. The only problem I have is that the capacity tracker resets if it's unplugged long enough. I believe it's powered by a capacitor that loses charge over time. This is not a problem if you fully discharge your device and then fully charge it.

Kapro 307-08-TMS Try And Mitre Layout And Marking Square With Stainless Steel Blade, 8-Inch Length
18 Review

π² Johnson RAS-1B Johnny Square: Professional Aluminum Rafter Square, 7'', Silver - Top Quality with 1 Square
8 Review

β Stainless Steel L-Square, Size 3-Inch x 4-Inch, Zona 37-434
8 Review

π Johnson Level and Tool 400EM-S 12-Inch Heavy Duty Metal Combination Square for Professionals, with Inch/Metric Measurements, Silver - 1 Square
8 Review