what is flipper-tunion fr?

flipper-tunion is a plugin for the Flipper Zero, the pocket-sized multi-tool popular with hardware tinkerers. It reads China T-Union transit cards, the contactless smart cards used for buses, rail, and other public transit across many Chinese cities. If you have a card from that system and want to inspect what's stored on it, this tool lets you do that directly on the Flipper device. When you tap a card with the Flipper, the plugin reads the data and displays a straightforward breakdown. You can see the card's primary account number, its issue and expiration dates, the region and city it belongs to, and the current remaining balance. It also pulls up ride history, showing timestamps for when you tapped in and out of transit gates, plus a log of recent transactions. There's additionally an NFC field tool for experimenting with LED-equipped cards, such as a special edition card from the Liaodong Peninsula. This is useful for anyone curious about what's happening behind the scenes when they tap a transit card. Transit operators, security researchers, and hardware hobbyists who ride transit in China can use it to verify card balances, audit trip logs, or explore how the card communicates with readers. It's a practical tool for anyone who wants transparency into a card they carry every day. The plugin is written in C with a simple text-based interface, designed to work with any Flipper firmware rather than requiring a specific custom build. The author notes another project in the same space that has a richer interface and a station name database, but this one prioritizes fast load times and a small footprint. It trades polish for speed and broad compatibility, which makes sense for a quick-check tool you'd run on a portable device.