I'd like to chime in as well. I believe its app related too but it's not necessarily the app itself but possibly the way it installed on the phone. A bad install can set your phone to overclock, so to say, for a variety of things. To test for this uninstall recently installed apps, restart your phone and charge it fully. Reinstall suspect app or apps one at a time giving ample time between installs to test for battery drain.
Another way is to uninstall suspect apps and reinstall them and most likely your battery trouble will be gone. Here is the other kicker in this deal; if app updates start causing issues, it’ll be harder to find the suspect.