Hi Nils,
Not sure if you have already gone through Kapsel based app development in SMP 3.0 . It is an HTML5 based app development. In general, kapsel is a set of plugins that enhance Apache Cordova with functionality such as a stream-lined logon to an SMP 3.0 server, the ability to update deployed applications, encrypted storage and push notifications.
Have a look at Getting Started with Kapsel - Part 1
Regards,
JK