We just published a basic version of our Android Closeness App on GitHub. It has been made available under a Creative Commons Attribution ShareAlike 4.0 license.

This slightly stripped-down version of our Closeness App starts an Android background service which continuously checks whether one (or more) of our custom bluetooth temperature discs is nearby. If the service finds the bluetooth signature of a disc, it reads out its broadcast signal, registering its id, the strength of the signal (representing the distance to the disc) and skin and environmental temperatures and syncing this data over a Android SyncAdapter  with a remote server.

The remote server runs a customized DreamFactory open source RESTful backend API which provides access to a NoSQL database.