OK, so bear with me. I am new to iPhone, having come from the Android world. I am looking for a battery usage app. Having looked through the myriad of battery apps ad nauseum, I have yet to find what I am looking for. All the apps want to tell me how much battery usage I have left if I use certain features of the phone. Is there one that can tell me how long I have been off charge and what apps are using battery? Seems simple, but maybe not. Thank you in advance.