I tried it, and I'm wondering what the hype is about. Not because of the idea, which is nice, but the implementation, which totally sucks. Very regular and very annoying crashes that waste items, severe server problems, burning through the battery as if it was calculating PI to a gazillion digits (this app is the only one to make my phone *hot*!), etc.
For some in-game advances (hatching pokemon-eggs) you have to walk certain distances. Ok, I know my regular morning walk distance, which is 2.4km. I had to restart this app eight times during this course, and it only "got" about 1.5km due to that fact that it does not count while being crashed (crashing is not that obvious, the display still follows your path on then virtual map, but the background process(es) that count distance, provide new pokemons, or allow intercations or item access is/are gone). Or you try to catch a pokemon - you spend a bunch of those "pokeballs" to catch it, and when you got it, the game freezes. The pokeballs are gone, and of course the pokemon is, too, after you restart the app. Well, and restarting (or starting in the first place) is just trying your luck. During the day it is "just" difficult to start, but after work or on weekends, the app does not even complete the loading screen. It usually hangs at the point where it connects to their server(s?) and thats it. As the server capacity problems have not been fixed after a week, I guess the server side simply does not scale (which perfectly matches the apps quality). That I get the game to start during my walk might be due to the fact that I walk while most of the teenagers are still in bed
Worse of all, people complained about the loss of bought items (e.g. you can buy those pokeballs if you are to impatient to "harvest" them), so I and maybe some other, more cautious people will wait for the software to getting into proper production status before spending a single cent on anything).
The version number of the app tells an developer that this software is basically not ready for production (0.29.2, a clear indicator for it being beta, if not alpha), and as unripe and buggy it is, it is an insult to the user. No reaction to the bug reports (they just generate an auto-answer that they won't reply to bug reports), and nearly 200k users giving that app only one star due to the bugs. And even those who give more stars more often than not complain that the app is buggy. I don't understand those idiots - If an app crashes regularly, why do they give five stars?
All in all, a nice new gaming idea, but with a total failure of an implementation. I have not heard of the development company (Niantic, Inc.) before, but from this experience, I would not let them develop even a "hello, world!" program for me.