Upgrade Firmware

Update your t-mobile lg g3 D851 to android lollipop by flashing blisspop custom rom.T-mobile lg g3 is powered by a quad core snapdragon 801 processor clocked at 2.5ghz with 3 gb of ram along with 32 gb internal storage.It has a 5.5 inch quad hd display which is protected by corning gorilla glass 3 protection layer.There is a 13mp front shooter paired with a 2.1mp front cam which can record 1080p videos too.

It comes with android kitkat on board and international variant is upgraded to android lollipop 5.0.If you want latest version of android that is android 5.1.1 the you the only way is to go for a custom rom on lg g3.We are going to flash blisspop rom to upgrade it to android lollipop 5.1.1.

Since this is specific to t-mobile lg g3 variant make sure that you are flashing this on this variant only as flashing this on other variants of this device might result in brick.To check your device model number go to settings and then to about device.You will find your device model number and confirm it as D851.

Why to go for a custom rom on T-mobile lg G3 D851?

• Less bloatware: Usually Carrier variants comes with lot of bloatware and unwanted stuff.This might hinder performance a bit which might result in laggyness.Custom roms will have less bloatware or no bloatware at all as a result of which you will notice its performance is much better than on stock rom.
• Better performance: Though performance can be increased by controlling cpu and Gpu  with root apps you might not achieve what you want.There is better scope for performance on custom roms as developers implements different mods to make it perfect.
• Battery life: Battery life is always opposite to performance.Greater the performance least the battery life  you get.In order to get a balance one between them you have to go for custom roms. 
• Better customisation: Most of the apps with root access will work better on custom roms than on stock roms.For instance take xposed installer.It offers lot of modules for customisation but will work perfectly on custom roms than on stock one.

Install blisspop rom on T-mobile Lg g3 D851:

Prerequisites:

• Charge your t-mobile Lg g3 D851 to at least 80% .
• Backup all your apps and data on your device to external sdcard or computer as flashing blisspop rom will erase all the app data on your device including contacts.
• Enable usb debugging on your Lg g3 D851.Of course you don't need to do this for sure but enable it.
• Download blisspop rom and gapps if you need them.Transfer them to your device internal storage
• Backup Efs and modem partitions of your Lg g3..
• You must have Clockworkmod recovery installed on your phone.

Blisspop custom rom:

Blisspop custom rom is based on cyanogenmod 12.1 rom with lot of added features with improved performance and customisation.This rom offers all the features that cyanogenmod 12 has to offer and also there are lot of added features from other popular roms too.This rom offer wide range of features from status bar to lock screen.Bliss team officially supports t-mobile lg g3 D851 so you will have updates much quicker.

• Statusbar tweaks: Status bar tweaks include notification count,network speed indicator,double tap to sleep ,brightness control and weather in status bar header.
• Recents panel tweaks:The recent panel has a button to clear all the tasks and omni switch is present is present as an alternative to traditional recent menu.
• Gesture anywhere:Gesture any where is also available which  makes it easy for you to launch apps with gestures instead of returning to home screen and app drawer to launch apps.
• App circle:In addition to this app circle bar is also present which makes it too easy to launch apps with just a swipe from the edge of the screen.
• Soft Navigation controls:You can enable soft keys too if you like them and also set the dimension  of the navigation keys and also you can define custom actions.
• Capacitive buttons: hardware keys have an option to adjust back light duration of the button and now you you can do various things with the just home key like accessing a call with just a tap on home key , wake the device and also you can set custom action for double tapping on home key.
• Power button: Press and hold power button you will have various options including soft boot ,reboot recovery ,screen reorder,air plane mode,screen shot,user switch and lot more.
• Animation control: You can set custom animation for app opening and closing,scrolling up and down.There are lot of animations available to choose from.
• Display and light:This includes live display,adaptive display,rotation mods,wake device on plugging in charger or usb cable,Custom DPI and change font size according to your needs.
• Cyanogenmod Camera app is built in.
• Other mods include audio Fx equaliser,security options,bliss pop ota updates and all standard android features.

Flash using Twrp Recovery: