If you need to move the game to another device, your in-app-purchases can be restored (as long as you sign in with the same username), but it is currently not possible to transfer the money you have as winnings over to another device.
Also the souvenirs and statistics are fixed to the device at the moment.
We appreciate that the bank balance does become very important to some of our players who get quite attached to it during their progress!
We are investigating ways that we could keep the money balance attached to an external account to enable you to move it more easily or keep it backed up against the possibility of a device reset. This would likely be via a Facebook account (which may be the easiest way for us to make it cross-platform), but there are quite a few technical challenges to make this happen, so it isn't in our immediate list of future updates just yet.