Bluetooth API won't give useful fingerprinting information
unless the user allows it with a very obtrusive prompt.
It's not something that's useful to the majority of websites, but I find it extremely useful for hobby ESP32-based electronics projects. It gives an easy way to configure individual boards, with no weird captive WiFi portal required. It's cross-platform (Windows, Mac, Linux, Android, just not iOS), and no native app required, an an easy-to-use API. This means means a lot less development overhead for my hobby projects. And it means I can give devices to family & friends without them needing to fiddle with firmware to configure the device.
On the device side I've used a lot of code from the CanAirIO project: https://github.com/kike-canaries/CanAirIO. I do want to switch my code to the NimBLE stack instead of the default bluetooth stack at some point - apparently it uses a lot less memory.
It's not something that's useful to the majority of websites, but I find it extremely useful for hobby ESP32-based electronics projects. It gives an easy way to configure individual boards, with no weird captive WiFi portal required. It's cross-platform (Windows, Mac, Linux, Android, just not iOS), and no native app required, an an easy-to-use API. This means means a lot less development overhead for my hobby projects. And it means I can give devices to family & friends without them needing to fiddle with firmware to configure the device.