the possibilities for/of
With technology having become more and more sophisticated and computer chips smaller and smaller, it seems the possibilities for smartwatches are almost endless.
-Is "the possibilities for" correct? I think it should be "the possibilities OF".

Just as the example from the Longman Dictionary－There was no possibility of changing the voting procedure.
(http://www.ldoceonline.com/dictionary/possibility)

Question

the possibilities for/of
With technology having become more and more sophisticated and computer chips smaller and smaller, it seems the possibilities for smartwatches are almost endless.
-Is "the possibilities for" correct? I think it should be "the possibilities OF".

Just as the example from the Longman Dictionary－There was no possibility of changing the voting procedure. 
(http://www.ldoceonline.com/dictionary/possibility)

Answer

Both sentences are correct.  "for" is used when something or someone receives a benefit. The meaning is similar to : "... the possibilities which smartphones now possess (have) ..."

In the second case, we are specifying the "possibility".  It's not just any possibility, but the very specific one of "changing the voting procedure".  "to be not possible to + do something" = "there is no possibility of something"

Answer

I may be wrong, but both seem to work.

You can also clarify by changing "possibilities" to "possible capabilities" (what they can do) or "possible applications" (what they  can be used for)