After giving up on the existing REST framework I made some progress on the client side of things. I took my basic example and formed a small Java library out of it.
I still have some problems with sometimes not getting notifications from items on sub-pages, I need to investigate that. Also, I should properly document the API before I release that library.
Since I want to have a small Android client for my project, I started learning about Android development. I installed Android Studio with all the prerequisites (and some libraries). First step will be to include my library and to get it run under Android. Then I can start trying to get the state of one of the sensors into the widget.
Maybe I should also add a minion somewhere? Would this one look good as logo:
Or should I wait for another week to choose from?