battery apps also poll the battery, resources constantly, so they're an added drain (something to consider). the meter in teh display window should be adequate for what you're doing. once you're used to the positioning of the graph, vs. what the current status is, you'll learn how to read when to charge, etc.
Yeah but that icon on the notification bar to me just doesn't update enough in my opinion. It will show half full when my battery less than 30% which isn't really all that useful.
Right now it showing almost full, just one "tick" below full, yet my battery is reporting 70% so really i'm somewhere between 60 and 70% yet the icon is like i'm just a tad below full.