Samsung Mega 6.3 CM12.1 LP5.1.1 SPH-L600 (DOWNLOAD)

ROM: Cyanogenmod 12.1 [unofficial] (meliusltespr)
Android Version: Lollipop 5.1.1 (currently LMY49H)

ABOUT: CyanogenMod (pronounced sigh-AN-oh-jen-mod), is a customized, aftermarket firmware distribution for several Android devices. Based on the Android Open Source Project, CyanogenMod is designed to increase performance and reliability over Android-based ROMs released by vendors and carriers such as Google, T-Mobile, HTC, etc. CyanogenMod also offers a variety of features & enhancements that are not currently found in these versions of Android.

CyanogenMod 12.1 New Features
This is one of the major features that CyanogenMod has added to their ROM in recent months. As described by the team, this feature automatically optimises the screen depending on the time and ambient conditions to reduce eyestrain and improve readability. It also allows users to change the color temperature and calibration of the display depending on the time of the day.

LCD Density: This feature allows users to change the software density of their phone. This will allow users to display more (or less) content on the screen depending on their preference. A lower number means more content will be displayed on the screen and vice versa.

Notification Manager: This is a new entry in the Settings menu in CyanogenMod 12.1/12. It contains options to enable/disable Heads up notifications, the ability to filter notifications from the installed apps, change priority of notifications of the installed apps, check the apps that can read notifications on the device and more.

Lockscreen visualiser: Google added a beautiful music lock screen widget to Android with Lollipop. CyanogenMod has further enhanced this feature in their ROM by adding a visualiser to it. When any music is being played, the lock screen will also display visualisations apart from the music controls.