I'm sure the Nexus tab has enough battery so it won't matter, but do be aware that battery monitor apps use battery, and not always just a little.
After running the
Carat App for a few weeks I was supprised to learn that all of my favorite battery monitors chewed up a lot of juice.
This is because they can induce the charge measuring chip to take additional measurements. And the only way you can measure the charge of LiPoly batteries is to do a controlled high-drain discharge for a short duration (a second or less), and measure the voltage drop of that event.
The system does this every so often, as well as watching the regular voltage drops, but many battery apps will induce more frequent charge measurement cycles.
So I just use the standard system gage and have stopped looking too closely, and stopped trying to micro-manage it. Its so much easier to let the machine take care of itself.