True Amps: Battery Companion - True Amps will show you important battery information such as amps, charging speed, battery health and temperature.
coconutBattery - With coconutBattery you are always aware of your current battery health. It shows you live information about the battery in your Mac and iOS devices (iPhone, iPad)
Accubattery - Monitor's battery capacity through the use of science
Fruitjuice - FruitJuice helps you keep your Apple Mac Laptop battery running and lasting longer.
GSam Battery Monitor - Monitor your android devices battery usage.
Battery Life - Battery Life is an app for Apple Watch and iOS devices that enable users to maintain and manage their device battery.