Battery Doctor, the professional power manager, is the best FREE battery saving app capable of extending your battery life. Over 150 MILLION downloads over Android and iOS worldwide supporting 19 languages. Defend Your Juice. - Disable unnecessary apps that drain your battery. - Task Killer kills tasks with one click. - Kill apps when screen is off. - Accurate battery remaining time. - Accurate charging remaining time. - Schedule power saving modes for work class or sleep and more.