"When I finished my No.2 step of building and attempted to text the second Bluetooth Hub whether it can normally work. Consequently, it cannot to connect to phone. I thought the first Hub repair successfully so that the problem is not from my phone or app, just up to Hub itself. I try to figure out why and follow the instruction to set it up many times. However, absolutely, it still keep being unconnected with app. I try to contact customer service by email. But I have to wait a couple days for response when I received the lego systemic replying email. there is only way to stop building and wait for solution. I hope It will be solved. I realize that the electronic component absolutely unreliable than the physical one, so that I don’t recommend this product."