7 cool and useful things to do with your Flipper Zero

The sub-GHz wireless antenna can pick up the signals from car key fobs (and can record them, although playing them back to modern cars won't unlock them because of a feature called “rolling codes” that changes the code with each use).

Also: The best security keys you can buy (and how they work) 

This is a handy way to test if the key is working and the battery is good.

NFC is everywhere nowadays, and the Flipper Zero allows you to work with this wireless protocol.

Note that while the Flipper Zero can read NFC cards, it cannot decode the card's encrypted security code, also known as CSC, CVV, CVC, CAV, and a bunch of other three-letter abbreviations.

Along with NFC, the Flipper Zero can work with RFID. Here it is reading a hotel key card.

Also: How RFID tags can make in-person clothes shopping less frustrating

RFID cards and tags can be locked to prevent them from being overwritten, but the Flipper Zero can bypass some of these mechanisms. Here it is offering to unlock the card if I present it to a valid reader.

Yes, the Flipper Zero can bypass the security on some Sentry Safe electronic safes using an output from the GPIO.

The Flipper Zero has a built-in infrared module, and this in turn can be programmed to operate a wide range of devices, from TVs to AC units.

Another cool use of this infrared functionality is to test if infrared remote controls are working.

Flipper Zero can act as a BadUSB device, which means that when connected to a port it is seen as a Human Interface Device (HID), such as a keyboard. 

A BadUSB device can change system settings, open backdoors, retrieve data, initiate reverse shells, or do anything that can be achieved with physical access. This is done using a set of commands written in the Rubber Ducky Scripting Language, also known as DuckyScript. 

The Flipper Zero can use the GPIO to output electrical signals and act as a signal generator. I last used this to simulate an ABS (antilock braking system) module on a vehicle to confirm that all the wiring and computer in the car were working.

Very useful!