Came across this app today while looking for something to show tablet info.I'm personally thinking it's not north worrying about, I charge all my stuff to 100%. Main thing I turn off is fast charge to reduce heat (which I had forgotten to do!).
I don't think it's worth reducing your enjoyment of the device by limiting yourself to a narrow window of use.
Might be useful if you're concerned about temperatures. Might also give you something else to check your WiFi speed with.
DevCheck is an Android app that tells you everything about your device