This simple app shows how to connect to BLE device and read some data from sensors. LEGO® Super Mario™ figure has a few sensors like rgb, motion etc.
Here you can find more info about sensors and protocol: https://github.com/bricklife/LEGO-Mario-Reveng
You can also sniff packets between Android and Mario using Wireshark:
enjoy!
3d model is taken from: https://3dmag.org/en/market/download/item/4240/