This paper describes the design of services to support consistency in collaborative mobile applications. The requirements for application level consistency in groupware applications are discussed and it is argued that existing consistency services for mobile environments fail to address these requirements because they assume infrequent (write) sharing of information. We present the design of a group execution service called G-QEX which is designed to support consistency in mobile applications and includes features necessary to cope with the fluctuations in QoS which characterise mobile environments.