Bought this drone to fight with a friend who had the same drone. The drone is easy to assemble and the iPhone app is easy to install and use. I was amazed at the distance the drones could fly from the controller - far more than any remote control car I had as a kid. My point is that while my friend's drone worked great when assembled, mine did not. He only lifted off the ground slightly and bounced off before the power was "cut off" and he fell to the ground. We assembled both drones the same way, so I guess it's just a marriage. HOWEVER, I contacted the seller regarding this and received a quick response with a video showing the correct installation (as users often misfit propellers) and helped me troubleshoot the drone. We could not repair the drone, so the seller sent me a replacement immediately. With such exceptional customer service backing their product and the fact that my friend's drone works perfectly as advertised, I still give this product the 5 stars it deserves. Update: I received a replacement drone quickly and it works great. I have a lot of fun flying the drone at speed 1 indoors and up to speed 3 outdoors. The drone is nimble in the air and the barrel roll trick is a great way to impress your friends. Would definitely buy again.