Licas (lightweight (Internet-based) communication for autonomic services) is an open source framework for building service-based networks, similar to what you would do on a Cloud or SOA platform. The framework comes with all of the required features for building and running services on the framework, including security features.
Licas Mobile demonstrates the potential of using licas for mobile development. You also need to download and run the free All-in-One GUI from the home 'Distributed Computing Systems' site, so you need to familiarise yourself with the desktop version first. The mobile app is essentially a file service for downloading files from your home server. It is also client-server only and not p2p. The architecture of licas is p2p and so the mobile app requires you to start a local server on your mobile device, but the operation is automatic and so the app behaves like a client-server application.
The free version offers functionality to connect to your remote server, browse and download files. The paid version also includes a search service that can find relevant files for you. The home server needs to run a file service only and it should probably set its root directory to the 'web' folder of the licas installation. The rest is very easy.