Here is another cool gift idea for LEGO fans. The LEGO Technic Cat D11 Bulldozer (42131) comes with 3854 pieces and everything you need to build your own app controlled bulldozer. It combines with the CONTROL+ app to let you raise, lower and tilt the blade and control the ripper and ladder.
This LEGO D1 measures over 10 inches high and 22 inches long when assembled. It has adjustable tracks. It comes with motors, hub, and all the necessary parts. You will need 6 x AA batteries for this.[where to get it]