Mobext, Havas Media's mobile arm, has appointed Warren Zenna as EVP, managing director, Mobext US. In his new role Zenna will be charged with developing innovative mobile experiences for brands and will be playing a crucial role in supporting Havas’ global strategy by spearheading Mobext in the US from the New York office. Prior to the appointment Zenna ran his own digital consulting firm, Zenna Consulting Group.