Unfortunately it is not possible to backup the data manually to iCloud or to any 3rd party backup application. Please use Facebook or Game Center to save your game data and sync it between devices.
By default loading cloud saves is turned on. You also have the option to turn this off or in fact choose which save you would like to load by turning on the ‘Cloud Load Confirm’ tick box.
This box can be found by navigating through the bottom left menu on the map and selecting the settings menu and then tapping on the cogwheel. Whilst on the first settings menu, that includes the audio options, you will see two small pips at the bottom. Select the second pip to access the second settings screen that contains cloud save options.