Almost a decade ago, the first phones appeared with hardware based TEEs, reaching today, all modern mobile devices contain a TEE. Despite the large-scale deployment, the use of TEEs functionalities has been limited to mobile device constructors and a closed community to develop applications for them. Moreover, the use of hardware-based TEEs in application development and research areexpensive and often proprietary. Nowadays, many industry associations like GlobalPlatform are working to standardize the specifications of the TEEs, so it is possible for any developer to create an application for TEEs, with a predefined standardization in a virtual trusted environment. This will help developers and researchers, to enhance the protection and functionality to new applications and services. This thesis deals with the development of a Trusted Application in a virtual Trusted Execution Environment, that makes use of all the security features this architecture provides. All of the tools and the development environment that are used, are common and well-known to the developer community. Finally, we would like to underline that open virtual TEE provides the ability to developers and researchers, of applications and services that have been developed, to be tested, refined and the continuation of development.