For $299/month, Udacity does a lot of work. I took a couple of their courses (could not complete) and those courses take substantial effort to complete. If someone is motivated enough to go through their (in my view) rigorous program, I could see how potential employers would be interested. More over there seems to be a shortage of solid Android/iOS developers. Solid training with Udacity's Nanodegree would be a definite plus.