Only had this lovely toy for about 24 hours and I'm already pretty blown away. Set it up with Xtreme firmware and with a bit of looking around online, managed to get marauder to work.
If marauder doesn't work, you need to flash the firmware first on the esp32 board which can be done from the Xtreme firmware following these steps:
1. Plug board to flipper
2. Apps > GPIO > ESP Flasher > Quick Flash > WiFi Dev> Marauder
3. When done, back out
4. Apps > WiFi > Marauder
5. Everything works as intended
Only problem I ran into is that you need to solder on a sd card addon board yourself and I found this board https://www.sparkfun.com/products/544
and more on this here: https://github.com/justcallmekoko/ESP32Marauder/wiki/flipper-zero#sd-card-modification
BadUSB works well. The IR is interesting, and already playing around with remotes. The RFID and NFC will def need a bit of exploring. I was pleasantly surprised by the amount of stuff like games. The companion app unfortunately doesn't work well on the Gemini PDA, and it would be nice if the app would be optimized for landscape mode. There is a better addon board someone sells for about $80 and probably will at some point get that board that has everything on it basically. The UART is also interesting and will def fiddle with that. Battery is excellent and Ralph is adorable.
Overall, so far I'm pleased I bought it for the all-in-one aspect and will probably give me motivation to go outside more.
I use it for managing the RFID keyfobs for my building. I can keep copies of each apartment's fobs -- which makes it trivially easy to disable lost fobs by using the 'delete' fob, followed by the lost fob (or all of the fobs for a specific resident), then re-enable new ones.
I've also played with the NFC toys, but the built-in capabilities are rather limited. I was able to copy a RFID hotel room key (a room which I was staying in) by cracking keys with the F0 itself, which just shows how terribly weak these things are.
I haven't been able to use the SubGHz module to do anything particularly interesting aside from cloning a remote control for a fan and an LED light.
It's a neat toy, and it absolutely exposes how trivially easy it is to break access control systems.