Currently in Alpha. Compatible with any Android device running 4.1+, with root and Xposed.

Power Nap for Xposed is the best app for saving battery. When your screen is off, Power Nap maximizes your device's deep sleep time by stopping services, alarms and wakelocks from waking the device when the screen is off. This means you can leave Wi-Fi/data on and still get the notifications from apps you have whitelisted, while all others are unable to wake up your device, leading to an increase in your battery life.

Power Nap for Xposed also has a Low Battery Mode, where you can selectively functions to save power when battery level is low.

Power Nap for Xposed is inspired by Sony's Stamina Mode, but accessible for all Android devices 4.1 and higher. This app requires root and Xposed.

Be sure to whitelist any third-party alarm clock app you are using, or it will be prevented from waking up your device!