Aquí is used in both Latin America and Spain but acá is only used in certain countries (not including Spain). Argentina and Uruguay (almost 99% of the time) do not use aquí, they use acá but in Mexico the opposite it true (aquí way more than acá).

In theory, "acá" is used with verbs of motion: "Muchachos, vengan acá." And aquí is used for for static location (i.e., location with no motion): "Los muchachos están aquí." But as with many things pertaining to life and language, theory is frequently ignored.

Yes , acà is used in "Latinoamerica" , aqui in spain ;)

Acá en Uruguay usamos tanto aquí como acá. Aquí en mi país se usan ambos,acá y aquí.