iOS app that shows a list of values to toggle on/off I'm looking for an app that contains a customizable list of fields, with a binary on/off or yes/no switch on each.

This is seemingly impossible to search for, given the generic words involved. 

The usage is: I carry three laptop battery bricks with unique serial numbers. As one depletes, I insert the next one. They all look identical except for the serial number, so it's helpful to make a note of which one is spent or not. I'd like a simple app where I can list the three, e.g., 


EZXXXXX
TYXXXXX 
FLXXXXX


With on/off switches next to them, so I can toggle and see at a glance which is spent. Often I wind up having only one with juice on it, and I have to cycle through all three and power the laptop on before finding the right one.
AFewThings on the JP app store. Excellent primitive (non-flat) interface, no ads, and you just add/delete a line and pulse it to turn strikethrough on or off. Finally, an app that does one thing and one thing only! And it's free!