Abstract: Apps are today the most important possibility to adapt
mobile phones and computers to fulfill the special needs of their
users. Location- and context-sensitive programs are hereby the key to
support the interaction of the user with his/her environment and also
to avoid an overload with a plenty of dispensable information. The
contribution shows, how a trusted, secure and really bi-directional
communication and interaction among users and their environment
can be established and used, e.g. in the field of home automation.