Tried Two Devices...Now Locked Out of Tablet

HELP!!

As a noob, I installed Airdroid on both my Samsung Galaxy S3 phone and Samsung Galaxy Note 10.1 Tablet. When I got the got the website up and running, it pulled up the tablet. I switched devices to the phone and the website showed me the phone.

However, when I switched to the phone, I got an email saying that the tablet was disconnected. AND HOW!!! Now I can't even get past the pin security on the opening screen. I'm completely shut out of the tablet! What should I do?

Have you used the Find Phone feature to set your tablet in Lost Mode?

Is it not possible to have more than one device signed on at a time? I have a Nexus 7 and both my wife and I have a Samsung Galaxy but attempting to sign in on more than one device logs me out. Am I missing something here? What good is it to only have one device signed in at a time?
I'm used to the "Find my phone" app in iOS where I could locate my wife's iPhone via my my iPhone. (We just switched to Android a few days ago.)