After Asus MeMo Pad, now its turn for T-Mobile LG Optimus L9. T-Mobile has been rolling out Android 4.1.2 to LG Optimus L9. New software version will bring new features like Project Butter, Google Now and many more.
Its international variant has already received update to jelly Bean. In order to update your T-Mobile branded device you need to charge your device more than 50% and it will be better if you use WiFi to download 350MB update. If you have already received the notification for update then sit back and update but if you didn’t received it until now then head over to your Settings >> About >> Check For Update. Currently update is available only via Over The Air (OTA). LG Optimus L9 received or is receiving  Software version P76920d and after update its baseband version is P76920d.
Currently T-Mobile is stating that it includes Jelly Bean only. For More information hgead over to the source below.
LG Optimus L9 was launched last year in the month of August and its the best device of LG Optimus L series which gained 10 Million sales in last month of 2012.
Some hours ago, T-Mobile also rolled out Jelly Bean update for Samsung Galaxy S Relay 4G.
Source: T-Mobile