This weekend I used a bit of free time to work on making a PirateBox to carry with me. I had upgraded from a Raspberry Pi Zero W to a Raspberry Pi 4 for my Funkwhale server and had freed up the Zero W to use for another task. The project builds an offline file sharing device that users can connect to over wifi from any device. The instructions were a breeze to follow.
PirateBox is a DIY anonymous offline file-sharing and communications system built with free software and inexpensive off-the-shelf hardware.PirateBox FAQ
One way I plan to use the PirateBox is as a way to share tabletop RPG books, character sheets and other media with friends when we get together to play. If we end up with no internet access, we can still get to those books and files we forgot to download to our devices and share content back and forth among the group. The device is tiny, so I expect to always be carrying it and be ready to play any game.