Hello there! :smokingsomb: I'm new here, and also relativelly new to mobile development so don't bother the possible imprecisions of my speech. I'm currently developing a music application, which scans an user music library and tries to find similarities with near music libraries using lastfm apis. I put the process of scanning library and building a database with the similar artists in a background service that wakes up when the user turns the internet on. The objective is to only use network in this process. With the database updated, I only need a way of passing information between different devices and it's important to me that this is a offline process (I think it's one of the valuable assets of my application). For my research, the only offline connection between devices I know is Bluetooth . However, as you know, this technology is kind of deprecated and it's not always reliable, principally because you can only communicate in short distances. Do you have a hint of doing this in other ways? I thought about socket connections, but for that you need to have a network connection. I also thought about creating this connection using ad-hoc networks programatically, but that I don't know if it is possible (at least, not in earlu versions of the android OS). Thank you very much, it is a pleasure writing in this forum!