Even if hardware improvements have increased the performance of embedded systems in the last years, resource problems are still acute. The persisting problem is the constantly growing complexity of systems. New devices for service such as PDAs or smartphones increase the need for flexible and adaptive open software. Component-based software engineering tries to address these problems and one key point for development is the Quality of Service (QoS) coming from resource constraints. In this paper, we recall the concepts behind Qinna, a componentbased QoS Architecture, which was designed to manage QoS issues, and we illustrate the developpement of a image viewer application whithin this framework. We focus on the general developpement methodology of resource-aware applications with Qinna framework, from the specification of resource constraints to the use of generic Qinna's algorithms for negociating QoS contracts at runtime.