When we create web applications, it is always with responsiveness in focus, to make sure the apps work on desktop as well as mobile devices. We build the apps with templating systems for reusability and dynamic frameworks for a good user experience even in complex applications.
When a responsive web application is not enough, but a real mobile app is needed, we always implement them using the technologies native to iOS and Android, to make sure we get the best performance, and the user experience that best fits each platform.
At the heart of an app, we often find a server that gathers all the data and makes it available to the various platforms. We can build this for a stand-alone server, or for a cloud service like Google App Engine, if automatic scalability is needed.