Creator of Worlds Achievement
Creator of Worlds10
Save 10 worlds to "My Toy Boxes".
These achievements require that you save one and then a total of 10 worlds to "My Toy Boxes." (i.e. the cloud). From with in a world you created, select the orange-ish upload button in the top left corner of the screen. Highlight Upload to My Toy Box, then choose Upload and confirm it. Create a name and then accept it. Once back in the list, repeat this process nine more times to unlock this achievement. Each save must have a unique name, but you can do this consecutively with an identical world.