Wao this is beautiful am happy to bring this good news to you Galaxy S4 SGH-I337users that Nougat AOSP Rom is now available all thanks to XDA Member -+BB+-,
Thing to Know
This Rom is for only AT&T Samsung Galaxy S4 SGH-I337.Do not try on any other Galaxy S4 Variants.
Your Android should be rooted and have a custom recovery installed to install this Rom.
TWRP Recovery will be used to flash this Rom.
This Rom will wipe out all data on your device. Backup, all relevant data before you, flashing the Rom.
Your device will not be detected by Samsung KIES after you flash this Rom.
Backup important files stored on your device before proceeding with below steps, so that in case something goes wrong your backup will help you.
Device variants supported: In this first alpha we support only international variants, CDMA won’t work, don’t try to flash it, I already know what’ s the problem, but I need a little bit of time for fix it. AT&T and Verizon users: since your bootloader is locked, you must be on the UCUAMDB or UCUAMDL bootloader if you own an AT&T phone, otherwise if Verizon you must be on the VRUAMDK bootloader to use this ROM. Do getprop ro.bootloader in Terminal Emulator or through ADB shell to find out which bootloader you have
TWRP Recovery v3.0.0-0 with F2FS support (JDC Themed): Download