Samsung Moment :: WARNING - CauseWorld Might Break Phone

I installed the update for CauseWorld (a random little app where you collect "karma" points for "checking-in" to various real-world locations, and then you spend the points on various charitable causes). I used to leave the app running all the time, so I could easily check-in to a new place every few minutes, because loading the app from scratch is frustratingly slow (whereas having it running in the background makes it pop up instantly).

With the new update, if I left the app running in the background, it'd wake up my phone every few seconds, as it tried to update my location in the app. So as I left my phone sitting on my desk, I'd see the lock screen flash on, then off. Then on, off, on, off, etc. Pretty annoying. Last night I charged my phone, and as I went to bed, unplugged the charger, since it was fully charged. But apparently I forgot to shut down the CauseWorld app, because my alarms never went off this morning, and my phone was completely dead.

I plugged it into the charger, but the phone won't turn on, even after leaving it plugged in for 15 minutes.
The only thing that's changed about my phone in the last week is downloading the update for the CauseWorld app, so I'm blaming that, for lack of any other idea of what caused the problem.