I don't intend to believe an app identified as snake oil and go from there.
Instead, I'm going to leave you with the following. What you do with the information is your business.
http://rationalwiki.org/wiki/Negative_proof
We can't seem to establish for you that the Battery Doctor is snake oil - therefore you believe what it tells you.
I could go into the details of teaching process monitoring in Android but you can do that yourself by googling "man ps" and "man top" to get the Linux user manual pages' definition, then run those commands in Terminal Emulator and send the output to a file for your forensic study.
Then you'll going to see all of the helper processes that Android is running and I suspect that at that point, we're going to be in to a full lesson on how *nix operating systems work.
We'll be well past your firsthand discovery that you were told the truth in the first place - that the app in question is a bunch of bullshit - and on to operating system theory. I took years to learn it properly.
We don't have time for all that so I've selected some high points.
Apps in Android run with intents.
Yes. Sometimes when you wake up one app - like your contacts - a signal occurs that triggers other apps - like the dialer or or your sms app - to get on deck so you don't have to wait for a cold launch.
Those signals are called intents. They're tightly managed and well controlled.
And outside of you tapping the screen or the foreground app calling for a background service, it's the only way that Android wakes up and runs things. (Apart from things like email that sleep, wake up to sync, sleep, wake up to sync, etc etc.)
Unless you're the geniuses at Battery Doctor who have discovered that omg pwnies, a camera can wake up 20 foreground apps and processes and omg only Battery Doctor can save you.
So rather than me continue to bicker about this, how about you look at each of those 20 apps and figure out how you can access each one from the camera.
The alternative to Battery Doctor NOT being snake oil lies in the proof that the many hundreds of man-years of system design and development leading to how Android works is just all nonsense.
http://www.vogella.com/tutorials/AndroidIntent/article.html
https://developer.android.com/tools/debugging/debugging-memory.html
https://developer.android.com/training/articles/memory.html
And after you've digested that, discover that Android already has a very sophisticated task killer whose collective developers make the creators of snake oil apps appear to be the brain damaged monkeys that they are -
http://ajqi.com/android-memory-management-and-its-effects-on-multi-tasking/
But if you want to believe that Battery Doctor is killing 20 apps every time you launch your camera, great. Run it. Let it screw with the entire operating system. Why not.
And the next time you believe what the snake oil tells you, just remember that you were warned -
That crap is like drugs. The more you use it, the more you need to.
All the while being convinced that it's a good thing.
Oddly, we don't download and use task killers on desktop Linux. Somehow, we all believe that the operating system works.
But not when you put it on a phone. Gosh no. /sarcasm
You want to believe what Battery Doctor is telling you - fine, great. Run it. It's screwing with the operating system and convincing you that the operating system doesn't actually work but if you like it, run it.
edit/ps - I have a habit of oversimplifying intents. Scary alien has a habit of posting and explaining it properly and I appreciate that very much.
Droid-den had a great write-up on this, but evidently, the site is down or le3ky ended it.