Info
Today I've ported an app to allow the LG Optimus F family excluding the F5, to backup & restore your EFS partitions. Backing up your EFS Partitions are extremely important because it's what basically makes your phone, a phone. Your IMEI, ESN and MEID numbers are all stored on these partition, if any of these data should ever be corrupt or deleted somehow *believe me its happened before* your phone will become useless when it comes to texting, calling, and surfing the web. Which makes it crucial that you backup your EFS partitions with this app so that if something should ever happen to them, you can always restore them.
Instructions:
1. First download LGBackupEFS.apk and install it
2. Open the app and give it root access
3. Tap on the Backup *It might look like the app froze but it didn't so DO NOT exit the app until it says its done*
4. Check to make sure the backups are on your internal sdcard in the directory /EFS-Backup/Model#/
5. Now if you ever need to restore your EFS Partitions tap on restore obviously lol then reboot.