BT or Wifi with Arduino Nano


I do a robot controlled by Arduino Nano.Now, I want to send orders to Arduino by Bluetooth or Wifi with my Android phone mobile. What kind of tecnology may I use with Arduino Nano? what is more cheap BT or WIFI? What platform is compatible?

Thanks a lot.

For smaller range ill go for the Bluetooth tech.. It is cheaper and much easier to program...

But again, it depends of your wanted range.

well?BT will be cheap &easy,
it works within 10m,and there are Android softweras for BT
like Blueteeth Serial Assistant(i translated the name XD)
and you can send orders to your robots by BT serial
i’ve tried it?and it works well