So you would like to control your LEGO creations with your smartphone? The BuWizz 2.0 has you covered. It lets you remote control Power Functions from your iOS or Android device. It has a range of 100ft and 4 speed modes. BuWizz has 4 pots for motors and lights.
The BuWizz weighs under 50 grams. You can find out more about it here.