magno castillo suggests: there is still too much difference in size between the largest and smallest. I think the smaller should not be less than 1/4 of the largest.  At the end you have to freeze size so it is nice.

My take on this question: Currently I limit it to 10 steps (variance), but I can imagine it is too much for some. Another way it could be to still have 10 steps in sizes, but the size differences could be limited (the smallest would be maybe quarter the size of the biggest as you suggest).  

My instinct it is to turn all of these into parameters which the user can set for each of their clouds. But of course such a move always increases the complexity of the app. 

Maybe I could then move some of these parameters to an “Advanced cloud parameters” card?
►Bubble spacing [seekbar]
►Size variance [seekbar]
►Size difference [seekbar]
►Hide pencil [checkbox]
►Delete dwarfs [checkbox]
►Freeze sizes [checkbox]

And the current “Cloud properties” card would be simpler:
►Name
►Background color
►Auto populate
►Re-measure widget

What do you think? I am open to suggestions!
Native English speakers, please help in the wording of
►Number of sizes (how many different sizes are in the cloud – some find it more pleasing to have just a couple of distinct sizes)
vs
►Biggest size difference (between the smallest and largest in the cloud)