Jelly Bean 4.2 GMail
GMail Jelly Bean 4.2 running on ICS 4.0.4 XXLRT
Downoad GMail42.apk here
1.You need to be ROOTED!
2.You need to have Root Explorer
How to install it?
1. Browse to "system/app" folder and rename original Gmail.apk to Gmail.apk1
2. Paste GMail42.apk downloaded and Rename to Gmail.apk
3. Change permission to rw-r--r--
4. Reboot. DONE!
Make sure you have click Mount R/W to Mount R/O, else you will fail to copy/rename/move file.