Perhaps if you describe what the formula is supposed to do we could come up with something that works. The SMALL function in Numbers does not take the parameters you are describing.
It looks like you want SMALL to return the four smallest values in the range C34:C38 and add them up. You could do this easily enough, but not using SMALL that way. It only accepts one rank parameter. The following would probably work.
=SUM(SMALL(C34,C38,1),SMALL(C34,C38,2),SMALL(C34,C39,3),SMALL(C34,C38,4))
At any rate, I think the curly brackets are for arrays. Numbers does not support this. I don't know about any of the other apps, but I doubt you'll find a mobile app that supports a function that advanced.