An increasing number of applications is being written for mobile hosts, such as laptop computers, mobile phones, PDAs etc. These applications are usually monolithic, featuring very limited interoperability and context-awareness and are usually difficult to deploy and update. Application engineers have to deal with a very dynamic set of environments that these applications are in contact with and it is becoming increasingly difficult to design an application that will be able to cater to all the user’s needs in those environments. This new setting forces a shift from design-time to run-time effort in developing software systems. To solve these problems and to allow a new class of ubiquitous and adaptable applications to be built, we have designed and implemented satin, a middleware system that allows the flexible use of logical mobility techniques by applications running on mobile hosts which are connected to very different networks. In this paper we describe our approach and show how satin can be used to deploy and update applications on mobile devices easily and efficiently.