Great question – you absolutely can. We just want you to be careful. Logging into multiple devices can increase the chance of losing data when switching from one device to another. In order to avoid the loss of data, it is important to
(1) Play online regularly (i.e. using wifi)
(2) Double check you are synced before logging out and switching devices
(3) Or have a designated player for a designated tablet
So if I have two children can they both use the app off wifi?
Assuming both tablets have followed the rules above prior to leaving wifi, then yes – you may have two children play offline, on two different devices, using two different players. However it is important to sync both players and log out after you get back into wifi.