I've updated the code of the nRF24Things application. The application is now working on Android Things DP5.1. There is a Bug on DP5.1 related to the SPI units. You can read more on my last post here.
I've tried to update the SensorTag-Things application but I didn't work. DP5.1 has still problems with Bluetooth. Due to the crash by debugging, I found and reported another bug to Google. Read here.