iOS is a really thoroughbred OS, combining stock capabilities and adopting jailbreak tweaks into the stock OS to fill it with really useful and exciting features. Among those exciting features is the Low Power Mode which increases the battery life of your iPhone by throttling down the performance and reducing the background activity, like disabling Background App Refresh, automatic Mail fetch, reducing motion, reducing brightness, etc.
Image : iOS 9 like Power Saving Mode on iOS 8
The Power Saver Mode is a brand new jailbreak tweak which does exactly the same in the iOS 8, though it works a bit differently. When the feature is enabled, it turns on the Reduce Motion and Increase Contrast options and disable Location Services and Background App Refresh. It turns off the Cellular Data in case you are connected to a WiFi network.
When you turn on the Power Saver Mode, the battery icon that is visible in the Status bar changes its color to yellow, thus indicating that the feature has been enabled, exactly alike the Low Power Mode in iOS 9. The feature will be disabled automatically when you connect the device into a power source.
Once you install the Power Saver Mode tweak, you can enable it by browsing to Settings > General > Usage > Battery Usage. A new toggle will be given here at the top of the pane which is labelled as Power Saving Mode. Just tap it to enable the feature.
The Power Saver Mode essentially does not bring the Low Power Mode from iOS 9 to iOS 8, as the native feature is more advanced and better as it also tweaks the CPU performance as well. But nevertheless, the Power Saver Mode tweak is good enough for turning off the unnecessary features that hog your battery. If you disable the Power Saver Mode, your device will return back to the previous settings.
Sadly though, the Power Saver Mode isn’t available on any of the stock Cydia repos. So if you want to install this tweak, then you will have to add a new repo in the Cydia sources first :
After you have added the above given repo, search for the Power Saving Mode and now you can locate and install it easily. It is a must try for all the jailbroken phones, so if you don’t have it yet, go get it!
Update: The Power Saver Mode has been updated. The new update provides options to enable or disable any of the features of this tweak. A few new features have been introduced too in the update, like disable auto-downloads, turn off auto-brightness, disable bluetooth if not connected to any device, etc.