That could also just be a bug. I remember installing an energy sucking application in 2014 on my Android; I think it was Expensify. I had noticed my battery was draining pretty fast, but then I noticed it took forever to even charge the phone. Upon closer examination, the app was consuming like 65% of all the energy being used. It must have been a bug, as there's no way they would make an app drain the battery that fast on purpose.