Read this: http://seriouspony.com/blog/2013/7/24/your-app-makes-me-fat
The title misses its mark in a body-image-positive crowd, but the real point of the essay is VERY important, and makes me seriously consider which apps I'm carrying around on my phone. The point, one I've heard before but perhaps not associated in the relevant way, is this:
Willpower and cognitive processing is a single, limited resource for any given brain. It's not just time we waste on our silly little app games. Far more seriously, we're wasting cognitive energy. We can boost it back up again with glucose, sure - a bit of protein, an electrolyte-heavy drink. But that only helps so much, and there's still a cost.
The author is focused on the implications for app developers - what are the ethics of designing your app or site to psychologically seduce/coerce users into spending their time and thus cognitive energy on you when there's little to no value to them?
As a user, I'm confronted with the realization that even if I enjoy my little puzzle games, I may actually be making myself a less functional person by playing them too often. I don't regret the time I put into a larger, more satisfying game like Legend of Zelda or Dragon Age, but if I never touch FarmVille again, not only will I not miss it, but I'll actually be a better, more functional person.
Now if you'll excuse me, I have some apps to delete.