tried and it work perfectly... here some guide for those who wanna get it to work:

1. uninstall the old version
2. root access to delete ALL wazapp/whatsapp related folder
3. reboot
4. install cepi latest .deb build
5. launch app, it will sync those group message where you've joined
6. WAIT...... till it's done
7. sync the contacts
8. done

Improvement seen from cepi ver vs the 0.26

1. Group chat with all features (photo/title change)
2. Contacts name displayed in Group Chat
3. Very nice UI
4. Very nice incoming alert vibration/sound
5. Full emo icons
6. Media sharing download ok, upload still buggy
7. No camera direct intergration (yet?)

Very well done porting from Cepi...