You'd have to examine exactly what is meant by "battery app". As of Android 2.2, task killers, often cited as "killing unnecessary background apps, thus saving battery" are generally not needed. Android does a decent job of releasing resources and managing memory. At the time of release, a lot of people were running various task killer apps, and testing showed that in many cases, killing a task that would then be automatically restarted by the OS consumed more battery in the long run.
There is another class of app that gives you more granular control over power consumption. I'm fond of "Green Power" myself. These will do things like turn wifi on or off with the screen, and allow wifi to be enabled for a fixed duration for background sync without staying on all the time. These don't kill background apps, and can work well. Note that CyanogenMod, the free OS that N2A sold you, has enhanced power management features that may work better than an add-on program.
I would suggest removing either sort of app if you're doing troubleshooting, as they do operate at a pretty low system level and can complicate pinning down your problem. I do like to go through and delete unused saved SSIDs once in a while, and deleting (forgetting), then reconnecting to your wifi network might help. I don't have an HD/+ device, so I'm afraid I can't offer much more help specific to your wifi issues.
This seems to be an issue with 4.4 Android. My HTC One has started doing this since I got the upgrade to Kit Kat.
My wifi uses MAC whitelisting and the network password is ginormous. I don't know if those are relevant factors or not, but it's been ongoing with this version from day one.
[...] could a battery app cause my HD+ on 4.4 to forget my network? I never exerienced the problem on Android 4.2.
A couple more thoughts on that specific question:
- Any system-level program such as a battery saver is a prime suspect, particularly if it was written for an older version of the OS than you're currently running. Definitely remove it until you're both sure it's still needed (it may not really be helping) and that it is not causing problems with newer Android versions.
- I believe the current stable version of Cyanogenmod is 10.2, based on Android 4.3. Definitely try the stable version before giving up. With an unstable branch, problems are to be expected, as is stated on the Cyanogenmod site. Unless you absolutely must have a new feature, there's no reason not to stick with an older, stable version that has worked for you. Your B&N software is most likely a far older version!
@bobstro: thanks for all the insights. Knew I could count on you.