We have vaste experience implementing enterprise level requirements and scalable solutions - web apps, web services, SSO, security, integration...
We are established as provider of portal solutions based on Liferay platform. We like Vaadin as front-end framework for writing portlets.
We have experience with development of native apps for both iOS and Android. We are also writing web apps that look great an a mobile device.
We are promoting responsive design whenever it makes sense. We don't when it doesn't. It's a useful tool to achieve realistic goals, not a buzzword.