If you have registered your account with an email and password before, you will be able to restore your account at a later time. Please follow the steps below: 

To restore your account:
1) Download and install Storm of Wars
2) Launch the game
3) After finishing the tutorial, tap 'Menu' 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'