After installing 8.5.3 and a new release of Extension Library I started to play with the Mobile controls included in it. It was originally a separate project on OpenNTF but now the controls are part of library itself. So you need 8.5.3 server (with extlib installed on it) to run apps using these controls. Thanks to new updateSite.ntf included with 8.5.3 it is now far more easier to deploy ExtLib to your server.
If you're (like me) using Extension Library in all your XPages applications and therefore you need to install it on all servers your aplications run on, then Plugins Deployment for Domino project is what you'll like a lot. Believe me.