CyanogenMod is Dead as of 31/12/2016 but the code of CyanogenMod has gave birth to Lineage OS and its just a branding change with few tweaks and not to worry as soon there will be lot of Official ROM builds for many devices and it work pretty much the same as CyanogenMod if not better.
Well we are not sure but there are developments happening to the source code of the phones and soon after that we expect them to build and announce the Official ROMS. But if you cant wait until then no problem! Developers are working round the clock to bring the experience to these devices and many devices have already gotten these. But the catch here is that it may not be complete or even stable,and maybe an half baked version plus these are Unofficial Versions.
Disclaimer:-This is an early build and may not be stable heck! it may not even boot. Have a complete backup before Flashing this. Try this at your own risk you could even brick your phone
Note:- All the required Links are at the end of this post.
Install Lineage OS on LG G3 Beat
1) You Need to have a Unlocked bootloader and have a custom recovery like TWRP flashed. If you haven’t already done then there is an Video on How to flash TWRP and root LG G3 Beat read it here
2) Take a Complete Backup of your Device. This is the most important step as if you screw up something you’ll have a complete backup so you can restore to the previous state. Here is a video on How to Backup your android.
3) Download Lineage OS for LG G3 Beat From Here. All thanks to the developer kn06497.
4) Download Gapps for google apps from here.
5) Copy the downloaded files to the internal storage of your LG G3 Beat.
6) Shut down your Android device and then hold Volume Down and Power button simultaneously to boot into recovery.
8) Go back to the home page of the TWRP then tap on –>”Install”, then navigate to the folder where you have copied the Lineage OS rom and the Gapps file which you downloaded before.
9) Select the –>”Lineage OS rom zip file” and then click on –>”Add More Zip Files”, then select the –>”Open Gapps Zip File”, then swipe to confirm the flash and wait until it gets completed. Have patience as it may take 5-20 minutes for installation. 
11) Now select your Language and configure your device like you would do when you have brought an new Android.
12) While configuring your google account if you are redirected back to the first stage of configuration then disconnect from the wifi and turn of your Mobile data and skip google account configuration for now and you will be good to go!
Links:-
Unlock bootloader and flash TWRP :- http://bit.ly/2iQngRE
TWRP for LG G3 Beat :- http://vasy.ru/TWRP/jagnm/
Download Lineage OS for LG G3 Beat :- http://bit.ly/2jwAzIp
Download Gapps for LG G3 Beat :- http://opengapps.org/
Devolper’s Website:- https://github.com/kn06497
I didn’t Install this as I don’t have an LG G3 Beat device and the Images may be different for you but the procedure will be 99% same below is the video where i install lineage OS on OnePlus 2 its just for reference. if you have any problem watch the video.
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