If they aren't going to such ridiculous extremes, then they're no worse than Facebook and company (meaning, measured use is reasonable.)
BTC Books, if you do try it on a phone w/o service and have issues, it would be good to know. I suspect you won't though.
Well, I got it onto an Android tablet without any trouble - no 3G and I disabled GPS. It's Android 2.3 though, so I can't get the 'send to yourself' option that I'm told is in Gyft's latest upgrade. So two users, two Facebook accounts (the new version of Google+ doesn't work on 2.3; it needs the Google Play Store (instead of the Market), which also doesn't work on 2.3), and two email accounts.
Yucch.
So my old smartphone is dead, but I'm getting a newer HTC in a couple of days from a friend for free. Runs Android 4 point something - ICS. We'll see if that's simpler, and if it works. I'll let you know.