You're asking about some specific apps. Most of which have not yet been implemented. Why they haven't been imeplemented is largely due to connecting qml and javascript in with the apis that is provided by skype, googlemaps, facebook, twitter ect.

Firstly you can find out how to install the Ubuntu Touch core-apps and run them from here and track their progress on the wiki

Based on your question, I dont think Ubuntu Touch is at the stage you want it to be yet. It is still interesting to play around with the SDK and try out some of the other apps users have created though.