If you want to play the same account on multiple devices, please follow the steps below.  

First, register your existing account with an email and set a password to protect it
1) From your old device, tap to open the Menu dialog
2) Go to Account and tap the button Register
3) Follow the instructions to bind your account with an email address and set a password. 

Then, restore your account on the other device(s)

1) On your new device, download Storm of Wars
2) Launch the game
3) After finishing the tutorial, tap to open the Menu dialog
4) Go to Account and tap the button Restore
5) Enter the bound email address and the password
6) Tap Restore

After the above steps, you will be able to play your account on multiple devices, but only one device at a time. 

If you decide that you don't want to play your game account on the old device any more, please uninstall your game account to ensure the safety of your account.