Battery Doctor
Features
Battery Doctor is a free app which keeps track of your battery power and how long it will last you. However, it goes beyond that simple feature with a few other helpful functions. Consider for example that this app will also estimate how long it will take for your phone to finish charging, alert you when you’re done charging, and keep track of your charging cycles. This not only insures that your battery’s health is maintained, but that you can also sell your phone for a better value with the testimonial that your battery is in good condition.
Mission Accomplished
If you want to know roughly how long your phone will last with its battery percentage, you can figure out how an estimate for a range of different activities ranging from playing music to playing 3D games.
Battery Doctor also makes it simple to clear your used memory and app storage cache to speed up your phone and make more room on it.
Room to improve
It’s not clear if the memory cleaning and cache clearing is an actual feature of this app, or if it’s just a “placebo.” As far as I know, iOS apps cannot clean the RAM of an iDevice without being jailbroken. Other than that though, this app is completely free and really useful.
Conclusion
If you want to keep track of your battery usage estimates, as well as keeping your battery in good health, then this is a must-have app.