Because I feel like I have to let others know about this important piece of information haha. I don't know if it's the same for everyone but at least from what I experienced, you can't be logged on two devices at once. The other device gets automatically logged out so if I were you, if you have still-to-be posted snaps on both your devices, tap on all of them first and make sure they are posted before logging on to the other. Unluckily for me, I didn't know this at that time. So all of my snaps, from the iPad and the iPhone, from when we left the house until we got home, are now gone. Poof! Vanished into thin air. Yes, that includes all my snaps from the concert. So yeah, now I know. Curse my need for chronology. Lol.