The use of smartphones has been increasing in the last few years. Many open standards and accessible Application Programming Interfaces (API) make it easier for developers to achieve their ideas and many communities, such as xda developers, or stackoverflow provide good questions and answers concerning mobile application development. Questions on how to search for available MNOs and how to switch a Mobile Network Operator (MNO) programmatically on Android devices already arose in 2010. Until the work concluded here, an answer of those questions have not been published. The main reason is that there are no methods provided in the public Android API that allows for performing such tasks. In this work here two mechanisms allowing for (a) an automatic and on-demand MNO selection and (b) an MNO look-up mechanism have been developed for the Android platform. The efficiency of these mechanisms has been evaluated with respect to power and time consumption.

Despite of the observed Cloud Services' (CS) heterogeneity, e.g., different APIs (Application Programming Interface), different accounting and charging models, and different security and privacy levels, one common aspect is that CSs provide a large amount of storage. CSs provide generic storage when it accepts to store data in any data type (e.g., Dropbox, Amazon S3). CSs provides data-specific storage when it accepts to store data only represented in specific data types (e.g., Google Picasa, SoundCloud). Therefore, PiCsMu (Platform-independent Cloud Storage System for Multiple-Usage) was developed to (1) aggregate multiple CSs' storage despite of the accepted data type, (2) provide enhanced privacy, and (3) enable a Peer-to-Peer (P2P) file sharing network relying on CSs' storage instead of peers' storage. The demonstrator use case shows how a PiCsMu user can upload, download, and share files with other PiCsMu users, specifically highlighting: (a) the hybrid approach used by the PiCsMu system, showing that CSs store data and the P2P network acts as a management overlay; (b) the PiCsMu social capabilities, showing that PiCsMu users are able to find and share content to existing Online Social Network friends; and (c) the fragmentation and data encoding, showing that both processes enable higher privacy levels since data is stored in multiple different CSs, and is imperceptible to CSs' data validation.