Is there a way to monitor and keep a log of CPU usage times for each process? Maybe through an app or mod or tweak. Is that even possible with a jailbroken device? I know the appStore doesn't have anything that can do this. Only apps I've seen are ones that list process and give current overall CPU usage, but that doesn't give logging or ability to pin point processes over time. I recall during the battery-gate incident, some users were asked by apple engineers to install some battery/performance monitoring app. So it is probably possible? For example, I would sometime leave my iPhone in my desk, fully charged, then come back later to find it dead. Usage time would say 3hrs 27minute, while standby time at 3hrs 44minutes. So something was running for that whole 3hours basically eating battery away. Doesn't always happen so it is hard to figure out what is the cause. Just leaves me guessing. Probably Mail/Exchange/Calendar looping, but not sure. I know there are lots of guides and advice on battery drain like turn this feature off or that, reinstall fresh, do this and that, trial and error. But, an app or tool like this would be very helpful in diagnosing what is causing battery drains. You would get more concrete information instead of guessing.