You don't need it per se.
Just back-up your whatsapp, contacts and contacts storage using Titanium Backup.
Install Root explorer pro and go to /data/apps and long-press on whatsapp. Then select 'send' to dropbox.
Flash any new ROM you want, like ICS and install gapps if needed. Download dropbox and download the whatsapp app you just uploaded to dropbox.
Then open titanium back-up (should still be there if you chose to back-up your market account with your installed apps). And restore the files for whatsapp, contacts and contacts storage.
Now open whatsapp and do the process of loggin in and it may ask for re-verification. Then you should have your contacts there. You only lost the names though, so you only see phone numbers.
I tried to export contacts to sd-card then import into ICS, but i wasn't able to do so.
|cm9, galaxy, ics, player, rom|
|Thread Tools||Search this Thread|